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JOURNAL OF THE AUDIO ENGINEERING SOCIETYAUDIO / ACOUSTICS / APPLICATIONSVolume 51 Number 11 2003 November

In this issue…

Subjective Distortion Metrics

Audio Encoding with VideoConstraints

Vacuum-Tube Distortion Analysis

Acoustics of Historic ChineseTheaters

Features…

Binaural Audio

New AES OfficersAES Sections Directory

The Audio Engineering Society recognizes with gratitude the financialsupport given by its sustaining members, which enables the work ofthe Society to be extended. Addresses and brief descriptions of thebusiness activities of the sustaining members appear in the Octoberissue of the Journal.

The Society invites applications for sustaining membership. Informa-tion may be obtained from the Chair, Sustaining Memberships Committee, Audio Engineering Society, 60 East 42nd St., Room2520, New York, New York 10165-2520, USA, tel: 212-661-8528.Fax: 212-682-0477.

ACO Pacific, Inc.Acustica Beyma SAAir Studios Ltd.AKG Acoustics GmbHAKM Semiconductor, Inc.Amber Technology LimitedAMS Neve plcATC Loudspeaker Technology Ltd.Audio LimitedAudiomatica S.r.l.Audio Media/IMAS Publishing Ltd.Audio Precision, Inc.AudioScience, Inc.Audio-Technica U.S., Inc.AudioTrack CorporationAutograph Sound Recording Ltd.B & W Loudspeakers LimitedBMP RecordingBritish Broadcasting CorporationBSS Audio Cadac Electronics PLCCalrec AudioCanford Audio plcCEDAR Audio Ltd.Celestion International LimitedCentre for Signal ProcessingCerwin-Vega, IncorporatedClearOne Communications Corp.Community Professional Loudspeakers, Inc.Crystal Audio Products/Cirrus Logic Inc.D.A.S. Audio, S.A.D.A.T. Ltd.dCS Ltd.Deltron Emcon LimitedDigidesignDigigramDigital Audio Disc CorporationDolby Laboratories, Inc.DRA LaboratoriesDTS, Inc.DYNACORD, EVI Audio GmbHEastern Acoustic Works, Inc.Eminence Speaker LLC

Event Electronics, LLCFerrotec (USA) CorporationFocusrite Audio Engineering Ltd.Fostex America, a division of Foster Electric

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IndustryJBL ProfessionalJensen Transformers Inc.Kawamura Electrical LaboratoryKEF Audio (UK) LimitedKenwood U.S.A. CorporationKlark Teknik Group (UK) PlcKlipsch L.L.C.L-Acoustics USLeitch Technology CorporationLindos ElectronicsMagnetic Reference Laboratory (MRL) Inc.Martin Audio Ltd.Meridian Audio LimitedMetropolis GroupMiddle Atlantic Products Inc.Mosses & MitchellM2 Gauss Corp.Georg Neumann GmbH Neutrik AGNVisionNXT (New Transducers Ltd.)1 LimitedOntario Institute of Audio Recording

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ADMINISTRATION

STANDARDS COMMITTEE

GOVERNORS

OFFICERS 2003/2004

Jerry BruckCurtis Hoyt

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Ronald Streicher President

Theresa Leonard President-Elect

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COMMITTEES

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SC-02 SUBCOMMITTEE ON DIGITAL AUDIO

Working Groups

SC-03 SUBCOMMITTEE ON THE PRESERVATION AND RESTORATIONOF AUDIO RECORDING

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TECHNICAL COMMITTEES

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SC-03-06 Digital Library and Archives Systems: David Ackerman, Ted Sheldon

SC-03-12 Forensic Audio: Tom Owen, M. McDermottEddy Bogh Brixen

TELLERSChristopher V. Freitag Chair

Correspondence to AES officers and committee chairs should be addressed to them at the society’s international headquarters.

Ray Rayburn Chair John Woodgate Vice Chair

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SC-05 SUBCOMMITTEE ON INTERCONNECTIONS

Working Groups

ACOUSTICS & SOUNDREINFORCEMENT

Mendel Kleiner ChairKurt Graffy Vice Chair

ARCHIVING, RESTORATION ANDDIGITAL LIBRARIES

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AUDIO FOR GAMESMartin Wilde Chair

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Jürgen Herre Cochairs

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Sporer Vice Chairs

AUDIO RECORDING & STORAGESYSTEMS

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PERCEPTION & SUBJECTIVEEVALUATION OF AUDIO SIGNALS

Durand Begault ChairSøren Bech and Eiichi Miyasaka

Vice Chairs

SEMANTIC AUDIO ANALYSISMark Sandler Chair

SIGNAL PROCESSINGRonald Aarts Chair

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AWARDSGarry Margolis Chair

CONFERENCE POLICYSøren Bech Chair

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EDUCATIONTheresa Leonard Chair

FUTURE DIRECTIONSRon Streicher Chair

HISTORICALJ. G. (Jay) McKnight Chair

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LAWS & RESOLUTIONSTheresa Leonard Chair

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NOMINATIONSKees A. Immink Chair

PUBLICATIONS POLICYRichard H. Small Chair

REGIONS AND SECTIONSSubir Pramanik andRoy Pritts Cochairs

STANDARDSJohn P. Nunn Chair

AES Journal of the Audio Engineering Society(ISSN 0004-7554), Volume 51, Number 11, 2003 NovemberPublished monthly, except January/February and July/August when published bi-monthly, by the Audio Engineering Society, 60 East 42nd Street, New York, NewYork 10165-2520, USA, Telephone: +1 212 661 8528. Fax: +1 212 682 0477. E-mail: [email protected]. Periodical postage paid at New York, New York, and at anadditional mailing office. Postmaster: Send address corrections to Audio Engineer-ing Society, 60 East 42nd Street, New York, New York 10165-2520.

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AUDIO ENGINEERING SOCIETY

AUDIO/ACOUSTICS/APPLICATIONS

VOLUME 51 NUMBER 11 2003 NOVEMBERCONTENT

President’s Message .........................................................................................................Ron Streicher 1011

PAPERS

The Effect of Nonlinear Distortion on Perceived Quality of Music and Speech Signals..................................................................................Chin-Tuan Tan, Brian C. J. Moore, and Nick Zacharov 1012

The subjective evaluation of nonlinear distortions often shows a weak correlation with physical measures because the choice of distortion metrics is not obvious. In reexamining this subject, the authors validated a metric based on the change in the spectrum in a series of spectral bins, which when combined leads to a single distortion metric. Distortion was evaluated both objectively and subjectively using speech and music. Robust results support the hypothesis for this approach.

ENGINEERING REPORTS

Ultra-High Quality Video Frame Synchronous Audio Coding..........................................................................Michael J. Smithers, Brett G. Crockett, and Louis D. Fielder 1032When audio signals accompany video information, additional requirements are imposed on audio encoding to allow for frame-based video editing, switching, and splicing. Moreover within the bit budget, the number of channels and their bit allocation is flexible. In the proposed approach audio blocks are designed to match the frame boundaries, but with an additional transitional region that avoids time-domain aliases, a degradation resulting when neighboring blocks are no longer contiguous.

Large-Signal Analysis of Triode Vacuum-Tube Amplifiers.......................Muhammad Taher Abuelma’atti 1046With the renewed interest in vacuum tubes, the issue of intrinsic distortion mechanisms becomes relevant again. The author demonstrates a nonlinear model of triodes and pentodes that leads to a closed-form solution when the nonlinearity is represented by a Fourier expansion rather than the conventional Taylor series. When applied to a two-tone sine wave, the analysis shows that the distortion in tube amplifiers is similar to that of the equivalent transistor amplifier. A SPICE analysis confirms the approach.

Acoustical Measurements of Traditional Theaters Integrated with Chinese Gardens................................................Weihwa Chiang, Yenkun Hsu, Jinjaw Tsai, Jiqing Wang, and Linping Xue 1054The acoustics of three Chinese theaters from the nineteenth century were evaluated using the conventional metrics for performance spaces. Similar to the Western tradition, theaters evolved as one of three types:amphitheater, courtyard, and auditorium. However, Chinese theaters were often integrated with privately owned gardens with a diversified design and acoustic architecture. Even with a high degree of spatial irregularity, measurements were consistent with modern theater acoustics.

LETTERS TO THE EDITOR

Comments on “History of Spatial Coding”....................................................................Peter Scheiber 1062

Why Is Bass Reproduction from a Dipole Woofer in a Living Room Often Subjectively More Accurate Than from a Monopole Woofer? .................................................................Siegfried Linkwitz 1062

STANDARDS AND INFORMATION DOCUMENTS

AES Standards Committee News........................................................................................................... 1064Standards in print

FEATURES

Binaural Audio in the Era of Virtual Reality .......................................................................................... 1066New Officers 2003/2004........................................................................................................................... 10732003/2004 AES International Sections Directory .................................................................................. 1078

DEPARTMENTS

News of the Sections ......................................1104Sound Track......................................................1108New Products and Developments..................1108Upcoming Meetings ........................................1109Available Literature .........................................1110

Membership Information.................................1111Advertiser Internet Directory..........................1112AES Special Publications ...............................1115AES Conventions and Conferences ..............1120

J. Audio Eng. Soc., Vol. 51, No. 11, 2003 November 1011

First, I want to express my gratitude to the member-ship of the AES for electing me as the next presidentof the Society. After having served as a governor, re-

gional vice-president, and then eleven years as secretary,when I reach the conclusion of this new five-year commit-ment, it will mark more than thirty years that I have been anofficer of the Society on the local, national, and internation-al levels. It has been and will continue to be my pleasure tohelp the Society grow and prosper throughout the world.

We all are aware that these are difficult times, not onlyfor the AES but the audio industry as a whole. The world’seconomy has slowed and the audio industry has not escapedthe downturn. Technological innovations have proven to bea double-edged sword, both creating and cutting job oppor-tunities for our membership; new forms of communicationsalso are both increasing and decreasing our production andsales markets. And, lest we forget, the social and politicaltroubles facing the world threaten even the basic safety andsecurity of many of our members worldwide.

Although the AES cannot solve most of the world’s prob-lems, we can dedicate ourselves to helping create a moreenjoyable lifestyle through the promotion and elevation ofthe audio arts and sciences throughout the world. While ourconventions are the Society’s most high-profile activitiesand the Journal serves as the public voice to all of ourmembers—as well as the whole of the audio industry—worldwide, I firmly believe that it is the meetings of the local sections that provide the most direct contact and bene-fit to our members. Therefore, it is the further developmentof these activities on the local level that I intend to make theprimary focus of my term as president. If we want to growthe Society, we must do it by offering our members—mostof whom never have the opportunity to attend our interna-tional conventions and conferences—something to attractand maintain their interest and involvement at a local level.

Among the goals of my presidency, therefore, will be towork with the Board of Governors to develop the followingnew activities for the Society:1) Creation and promotion of a Speakers Bureau of willing

and able people who can give meaningful presentationsto the local sections not only in their own home areas,but wherever their professional travels take them. Someof the features I propose for this project include:a) active solicitation of speakers at our conventions and

via the Journal and AES Website;b) establishment of a roster of regularly available speak-

ers, such as people who are retired or who travel regu-

larly on business and who can provide appropriateand meaningful presentations about their field of expertise;

c) an active “information brokerage” (at headquartersand/or via the Website) to maintain these speakers’contact information, availability, lecture topics, anditineraries and coordinate them with the regional vice-presidents and officers of the local sections wherethey will be visiting;

d) financial support (primarily reimbursement for ex-penses) for these speakers so that the incrementalcosts of their presentations will not have to be bornefrom the limited budgets of the local sections.

2) Increased coverage and promotion of local section activi-ties in the Journal, the AES Website, and the public andtrade press.

3) Creation of a regular quarterly e-mail newsletter, to bepublished from AES Headquarters. The primary purposeof this will be to promote upcoming local and regionalactivities (i.e., section meetings, regional meetings, andconferences) of the Society and serve as a means of dis-tributing information about and among the sections ofthe AES.

4) Encouragement of more local or regional meetings andconference events to augment service for the member-ship in areas where the AES does not hold its largerevents. Particular emphasis will be to stimulate activitiesin those areas—in all the regions—where there are noAES activities at all other than local section meetings.I fully realize that these are very ambitious goals—some

of which have been discussed for several years but withoutany development due to lack of appropriate available funds.To help bring these goals to fruition, therefore, I intend toseek special contributions (both private and corporate) to establish an endowment fund—the proceeds of which willbe dedicated solely to the support of the Speakers Bureauand other local activities. I invite anyone interested in con-tributing to this endowment fund to contact me directly.

With more than fifty years of history behind us, I wantthe AES to continue to be a strong and viable institution forthe next half-century and beyond, and with your help andsupport I know we can do it.

Ron Streicher, [email protected]

PRESIDENT’S MESSAGE

PAPERS

0 INTRODUCTION

All transducers (such as loudspeakers and micro-phones) and transmission channels (including amplifiers)introduce a certain amount of distortion. The received orreproduced signal is not identical to the original.Distortion can be broadly categorized into two types:

1) Linear distortion. This involves changes in the rela-tive amplitudes and phases of the frequency componentspresent in the complex signal. Such changes are typicallyperceived as changes in timbre or tone quality (coloration)[1]–[6]. In principle, distortion of this type can be com-pensated (within limits) by linear filtering, and such filter-

ing can be applied either before or after the transducer ortransmission channel whose properties are being studied.

2) Nonlinear distortion. This involves the introductionof frequency components that were not present in theinput signal. The effects of nonlinear distortion are diffi-cult or impossible to compensate by subsequent process-ing. Signals subjected to nonlinear distortion are oftenperceived as distorted. It is perhaps unfortunate that thesame word is used to describe both the physical processand the subjective impression. The effects of nonlineardistortion may be described as harshness or roughness orin terms of the perception of sounds that were not presentin the original signal such as crackles or clicks [7]–[9].

We have been conducting a series of studies with thegoal of characterizing, and eventually predicting, the per-

1012 J. Audio Eng. Soc., Vol. 51, No. 11, 2003 November

The Effect of Nonlinear Distortion on the PerceivedQuality of Music and Speech Signals*

CHIN-TUAN TAN, AND BRIAN C. J. MOORE, AES Member

Department of Experimental Psychology, University of Cambridge, Cambridge CB2 3EB, UK

AND

NICK ZACHAROV, AES Member

Nokia Research Center, Audio-Visual Systems Laboratory, Tampere, Finland

The effect of various types of nonlinear distortion on the perceived quality of speech andmusic signals was examined. In experiments 1 and 2, "artificial" distortions were used,including hard and soft symmetrical and asymmetrical peak clipping of various amounts,center clipping, and full-range waveform distortion produced by raising the instantaneousabsolute value of the waveform to a power (1) while preserving the sign. Subjects wereasked to rate the perceived amount of distortion on a ten-point scale (where 1 was mostdistorted and 10 least distorted). In experiment 1 the distortions were applied to the broad-band signals. In experiment 2 the distortions were applied to subbands of the signal. Resultswere highly consistent across subjects and test sessions. Center clipping and soft clipping hadonly small effects on the ratings, whereas hard clipping and the full-range distortions hadlarge effects. The subjective ratings were compared to physical measures of distortion basedon multitone test signals. A distortion measure, DS, derived from the output spectrum of eachnonlinear system in response to a 10-component multitone signal gave high negative correla-tions with the subjective ratings (correlations were negative as large values of DS wereassociated with low ratings). A further experiment was conducted using stimuli for whichnonlinear distortion was introduced by recording the outputs of real transducers. The outputsignals were digitally filtered to reduce irregularities in the amplitude–frequency response asfar as possible. The results showed moderately strong negative correlations between thesubjective ratings and the objective measure DS. It was concluded, that an objective measureof nonlinear distortion based on the use of a multitone signal can predict the perceptualeffects of nonlinear distortion reasonably well.

*Manuscript received 2003 July 11; revised 2003 September 2.

PAPERS THE EFFECT OF NONLINEAR DISTORTION

petual effects of both linear and nonlinear distortion. Wefeel that an essential first step is to characterize the per-ceptual effect of each type of distortion separately. The per-ceptual effects of linear distortion have been characterizedin another paper [10]. The present paper is concerned withthe effects of nonlinear distortion on the perceived qualityof speech and music. In what follows, the word “distor-tion” is taken to mean nonlinear distortion and not lineardistortion.

Distortion is typically measured using one or two sinu-soids as a test signal. If a signal sinusoid is used, the dis-tortion is often specified as total harmonic distortion inpercent. When two sinusoids are used, then intermodula-tion distortion is measured. Again, it is usually expressedas a percentage. These two measures are still used widelyfor characterizing the performance of loudspeakers,amplifiers, and hearing aids [11]. However, the perceptionof distortion is not closely related to the percentage of har-monic or intermodulation distortion. Perception depends,among other things, on the frequencies of the distortionproducts relative to the frequencies of the test signal. Forexample, if the frequencies of distortion products fall veryclose to the frequencies of the primary components, thedistortion products may be masked by the primary com-ponents. In contrast, if the distortion product frequenciesare remote from those of the primaries, the distortionproducts may be heard more easily. In addition, distortionproducts may interact with primary components to producetemporal effects (amplitude or frequency modulation), andthe audibility of these effects depends on the frequencyseparation and relative phases of the distortion productsand primary components. The simple percentages measureof harmonic or intermodulation distortion takes no accountof the frequencies and phases of the distortion componentsrelative to the primary components, and hence cannot cap-ture these effects. Furthermore, measures of distortionobtained using sinusoidal test signals may not be appropri-ate for representing the audibility of distortion in morerealistic signals, such as speech and music, whose ampli-tude fluctuates from moment to moment.

This point has been strongly made in a recent reviewarticle [8], [9]. The authors concluded that, “all attempts tofind simple quantitative ratios between conventionallymeasured nonlinear parameters and subjectively detecteddistortion have not been entirely successful” [8, p. 1027].They proposed, following the work of Risch [12], thatrather than using single-tone or two-tone test signals, dis-tortion should be characterized using a multitone test sig-nal with logarithmically spaced components. They sug-gested that “the application of the multitone stimulus withits ability to excite numerous distortion products of vari-ous orders” might help to provide a link between objectivemeasures of distortion and the subjective perception ofdistortion. In this paper we explore this link and attempt topredict subjective ratings of distortion using objectivemeasures obtained with a multitone signal.

The papers by Czerwinski et al. [8], [9] provide anextensive historical review of previous studies of themeasurement of physical distortion and the perception ofdistortion, particularly in the evaluation of amplifiers and

loudspeakers, and we will not attempt to provide a similarreview. However, it is noteworthy that parallel efforts weremade in the evaluation of distortion in hearing aids. Kates[13] proposed the use of a comb-filtered noise as a testsignal. The proposed noise resembles the multitone signal,except that the peaks are uniformly spaced on a linear fre-quency scale rather than a logarithmic scale. Severalresearchers have proposed the use of coherence as a per-ceptually relevant tool for characterizing distortion[14]–[17]. The coherence is the normalized cross-spectraldensity between the input and the output, and it has typi-cally been measured using random noise, pseudorandomnoise or a maximum-length sequence as the test signal.The measurement of coherence with noise-like signals hassome of the advantages of using the multitone signal“because it measures all forms of distortion and not justthe harmonic distortion traditionally measured” [18].However, this approach works well only with time-invari-ant distortion, and does not give reliable estimates of dis-tortion for hearing aids incorporating automatic gain con-trol. Kates [18] proposed the use of the phase variance ofthe system transfer function as a perceptually relevantmeasure of distortion. The phase variance can be esti-mated from the normalized input–output cross correlation,and it is relatively unaffected by changes in system gainproduced by automatic gain control.

Finally it should be noted that methods for assessingthe perceived quality of audio signals have been developedfor the purpose of evaluating bit-trade reduction systemsused in digital coding, complex audio processing, or trans-mission chains. Examples of such methods include thePEAQ standard ITU-R BS.1387-1 [19] and the PESQstandard ITU-T P.862 [20]. These methods are intendedfor use only with electrical signals, and not with signalsthat have been passed through electroacoustic transducers.Their ability to predict degradations in quality producedby nonlinear distortion in transducers has not beenassessed. Also, PESQ is intended only for narrow-bandspeech measurements (300–3400 Hz).

In this paper we first describe two experiments thatexamine the effects of a variety of “artificial” distortionson the perceived quality of speech and music signals.Some of the distortions, such as hard and soft peak clip-ping, were meant to resemble distortions that occur inelectroacoustic systems such as amplifiers and loudspeak-ers. Other distortions were not meant to mimic any physi-cal system, but were used to provide a greater variety oftypes of distortion. The two experiments were based onlyon static time-invariant nonlinearities. The perceptual datawere intended to provide a strong test of methods andmodels for predicting the perceptibility of distortion. Wecompare the perceptual data from experiments 1 and 2with physical measures based on the output of the nonlin-ear systems in response to multitone signals. A physicalmeasure, DS, based on the spectrum of the output, isdeveloped for predicting perceived distortion. Finally, wepresent a verification experiment, in which perceptualjudgements were obtained of speech and music signalsthat were subjected to nonlinear distortion produced byvarious types of transducers.


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1 EXPERIMENT 1: WIDE-BAND DISTORTION

In the first experiment the distortions were applied tothe entire waveform of the stimulus, resulting in wide-band distortion.

1.1 Types of DistortionThe following types of distortion were applied:1) Hard symmetrical clipping, with the clipping level

set so that the input signal was clipped 0.5, 1, 2, 5, or 10%of the time. The clipping levels were chosen based on dis-tributions of instantaneous amplitude for the entire stimu-lus, and were determined separately for the speech andmusic signals (details of these are given later).

2) Hard asymmetrical clipping, with positive peaks onlyclipped. The clipping level was set so that the input signalwas clipped 0.5, 1, 2, 5, or 10% of the time.

3) Soft symmetrical clipping, where the slope of theinput–output function decreased for large signal values,but did not become zero. The clipping threshold wasdefined as the input level at which the output level (for asinusoid) was 2 dB below the level that would haveoccurred if the system had remained linear. The clippingwas set so that the input signal exceeded the clippingthreshold 0.5, 1, 2, 5, or 10% of the time.

4) Soft asymmetrical clipping, with positive peaks onlyclipped. The clipping was set so that the input signal exceededthe clipping threshold 0.5, 1, 2, 5, or 10% of the time.

5) Center clipping, for which voltages within a certainrange around 0 V were set to 0 V. The clipping range was setto 0.5, 1, 2, 5, or 10% of the rms value of the input signal.

6) Full-range distortion produced by raising the instan-taneous absolute magnitude of the signal to a power α (notequal to 1) while preserving the sign of the magnitude.Values of α were 0.5, 0.7, 0.9, 1.1, 1.3, 1.5, and 2.

This gave a total of 32 conditions involving a widerange of types and amounts of distortion.

1.2 Test SignalsTwo sets of test signals were used, speech and music.

Digital representations of the input signals were obtaineddirectly from a CD, using the standard sampling rate of44 100 Hz. The speech was a concatenation of two sen-tences, one from a male and one from a female talker,taken from tracks 49 and 50 of the CD “Sound QualityAssessment Material” (SQAM) produced by the EuropeanBroadcasting Union.1 The overall duration of the two sen-tences, including the brief pause between them, was 3.1 s.The music was a fragment of jazz (piano, bass, and drums)with a relatively constant overall level, taken from a com-mercial CD (digital recording). The same fragment wasused throughout. Its duration was 7.3 s. The speech andmusic were processed off line, and the processed stimuliwere stored on computer disk.

The stimuli were replayed to the listener using a 24-bitLynx 1 sound card, mounted in a PC. The output of thesound card drove Sennheiser HD580 earphones. The same

signal was fed to each earpiece. These earphones have adiffuse-field response, that is, they produce at the eardrumof the listener a similar frequency response as would beobtained listening in a diffuse sound field. Thus theirresponse at the eardrum shows an increase in the fre-quency range around 3000 Hz, which reflects the reso-nance normally produced by the concha and meatus. Theearphones were calibrated using a KEMAR manikin [21],averaging the results for the “large” and “small” ears. Theoutput of the ear simulator was connected to a Hewlett-Packard 35670A dynamic signal analyzer. The frequencyresponse was compared to the mean of the diffuse-fieldresponses of the human ear measured by Shaw [22], Kuhn[23], and Killion et al. [24]. The response of the earphonewas found to match the mean diffuse-field response within±3.5 dB from 30 to 6000 Hz. Above 6000 Hz the responseshowed some irregularities, which varied depending onwhich ear was used in KEMAR and also on the exact posi-tioning of the earphones on the manikin. Additional meas-urements using a probe microphone (Etym~otic ResearchER7C) close to the eardrum of several human individualsshowed that the response above 6000 Hz varied from oneindividual to another, but that the response averages acrossindividuals was close to the diffuse-field response. Suchindividual variations also occur in the diffuse-fieldresponses of human ears [22]–[24].

We also measured the harmonic and intermodulation dis-tortion produced by the earphone, again using the ear sim-ulator and a Hewlett-Packard 35670A dynamic signal ana-lyzer. For sinusoidal inputs with frequencies from 100 to6000 Hz, and for sound levels at the output up to 90 dBSPL, the level of the distortion component corresponding tothe second harmonic was always at least 70 dB below thelevel of the primary component, while the level of the dis-tortion component corresponding to the third harmonic wasalways at least 84 dB down. Other distortion componentswere not measurable. For various pairs of primary frequen-cies, f1 and f 2, in the range 100 to 7000 Hz, and for levelsup to 90 dB SPL, the level of the distortion component atf2 f1 was always unmeasurable. For the same conditions,the level of the distortion component at 2f1 f2 was alwaysat least 73 dB lower in level than the primary tones, and wasusually unmeasurable. No other distortion componentswere measurable. We conclude that the distortion producedby the earphones was probably below the audible limit[7]–[9], [25], [26]. The distortion was certainly well belowthat introduced deliberately into our stimuli.

The overall level of each distorted signal was adjusteddigitally prior to digital–analog conversion so as to giveroughly a constant loudness of 86.4 phons (binaural lis-tening). The required adjustment was calculated using theloudness model of Moore et al. [27]. The calculations tookinto account the diffuse-field response of the earphones.

1.3 Experimental MethodIn a given test sequence of 32 stimuli, a listener was

tested using either speech or music. Stimuli subjected tothe different types of nonlinear distortion were presentedin a randomized order. After each stimulus presentationthere was a pause, during which the listener was required


1www.ebu.ch; materials also available from http://sound.media.mit.edu/mpeg4/audio/sqam/.


to rate the perceived quality on a 10-point scale where 10indicates “clean, completely undistorted” and 1 represents“very distorted” The response categories were displayedon the computer screen, and subjects responded using themouse to click on their category of choice. The computerwaited indefinitely until a response was made. The nextstimulus was presented approximately 1 s after a responsewas made. It should be noted that asking subjects to ratequality in this way is different from asking subjects tojudge the difference between the distorted signal and theoriginal. Sometimes specific types of distortion can actu-ally increase sound quality [28]. However, distortion ofthe type used here introduces intermodulation componentsthat are often not harmonically related to the original sig-nal and which always result in a degradation of soundquality.

To illustrate the meaning of the descriptors for the cat-egories, before the experiment started, samples were pre-sented of undistorted signals; these were described asexamples of category 10. Similarly, samples were pre-sented with large amounts of distortion (full-range distor-tion with α 0.5 or 2); these were described as category1. Each subject was tested in two sessions on differentdays. In each session the test was conducted once usingspeech and once using music. The repeated measurementfor each type of stimulus allowed us to assess how consis-tent the responses of each subject were. A session typi-cally lasted about one hour.

1.4 SubjectsTen subjects were tested. None had any history of hear-

ing disorders and all had audiometric thresholds betterthan or equal to 20 dB HL in both ears at all audiometricfrequencies from 250 to 8000 Hz. Their ages ranged from15 to 35 years (mean 24, standard deviation 6). Subjectswere paid for their participation.

2 RESULTS

1.4 Consistency across Sessions and SubjectsThe results for each subject generally showed a very

similar pattern across the two test sessions for a given typeof signal (speech or music). The overall consistencyacross test sessions was assessed by calculating the meanscore across subjects for each condition and stimulus type,separately for each session, and then calculating the cor-relation of the scores for the 32 conditions across sessions.The correlations obtained in this way were 0.988 for thespeech stimuli and 0.985 for the music stimuli. The veryhigh correlations indicate a high degree of consistency ofthe group mean scores across test sessions.

The pattern of results was also very consistent across

subjects. To assess the degree of consistency across sub-jects, we calculated the mean score for each subject andeach condition across the two sessions. We also calculatedthe mean score across subjects for each condition andstimulus type, including the data for both sessions. Then,for each subject in turn, we calculated the correlationbetween the scores for that individual subject and meanscores, over the 32 conditions. The higher the correlation,the more closely the pattern of scores for a given subjectresembles that for the group as a whole. The resulting cor-relations are shown in Table 1, separately for music andfor speech stimuli. The resulting correlations are high,indicating a high degree of consistency across subjects.The standard deviation (SD) of the ratings across subjectsfor a given condition was typically about 1.3 scale units(standard error, SE, about 0.4 scale unit).

For each type of distortion (such as hard symmetricalclipping) an ANOVA was conducted on the ratings withfactors subject and amount of distortion (such as clipping0.5, 1, 2, 5, or 10% of the time). This was done separatelyfor the speech and music stimuli. The scores for the twotest sessions were treated as replications. For each type ofdistortion, there was a highly significant effect of theamount of distortion (p < 0.001); ratings decreased in anorderly way with increasing distortion. For the full-rangedistortion, ratings decreased as α was made more differ-ent from 1 (either larger or smaller than 1). The effect ofsubject was sometimes significant, indicating that somesubjects gave lower or higher overall ratings than others.There were only two cases where the interaction of sub-ject and amount of distortion was significant, indicatingthat the pattern of results differed across subjects. Thesecases were for speech stimuli with full-range distortion(F(54, 70) 1.84, p 0.008) and music stimuli withasymmetrical hard clipping (F(36, 50) 1.88, p 0.019). In both cases the interaction term accounted forless than 2% of the variance in the data. We conclude thatthe ratings are mainly determined by the amount of dis-tortion in the stimuli, and that individual differences inthe pattern of ratings are small. In what follows, we focuson the mean ratings.

2.2 Mean RatingsThe mean ratings across subjects are shown in Figs. 1

and 2 for the speech and music stimuli, respectively. In gen-eral the data are very orderly. For a given type of distortion(such as symmetrical peak clipping), the ratings decreasemonotonically with increasing physical distortion.

Even for small amounts of distortion, the mean ratingwas never above 9.2 for speech and 9.0 for music. Thisreflects the fact that subjects tend to avoid the extremesof the available range of responses when making sub-


Table 1. Correlation of mean ratings across sessions for each individual subject withmean ratings across subjects, for experiment 1.

Subject 1 2 3 4 5 6 7 8 9 10

Speech 0.94 0.95 0.94 0.97 0.97 0.96 0.96 0.97 0.98 0.91Music 0.96 0.95 0.94 0.97 0.97 0.98 0.97 0.98 0.96 0.95

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jective judgments [29]. The lowest ratings wereobtained for the full-range modification with α 0.5 or2; the mean ratings were close to 1 for these cases. Hardsymmetrical clipping 10% of the time also gave low rat-ings, around 3.5 for speech and 3.1 for music. Soft clip-ping and center clipping up to 2% had little effect onperceived quality.

3 EXPERIMENT 2: BAND-LIMITED DISTORTION

In experiment 2 the distortion was introduced in afrequency-specific way, so as to gain insight into the rela-tive importance of distortion in different frequencyregions.

3.1 StimuliIn one set of conditions, referred to as prefiltering, the

stimuli were filtered into four frequency bands and thedistortion was applied to the waveform at the output ofone of the filters only. The four bands covered the follow-ing frequency ranges: 0–606 Hz, 606–1973 Hz,1973–5583 Hz, and 5583–22 050 Hz. The outputs of thefilters were then recombined. This meant that the distor-tion originated in a specific frequency band, but the result-ing distortion components were allowed to spread to otherbands, as might occur in a multiway loudspeaker systemin which one transducer introduced distortion. The filterswere designed so that the filtering and recombination did


Fig. 1. Results of experiment 1, showing mean ratings for each type of distortion for speech stimulus.


not lead to significant changes in the amplitude–frequencyresponse. The following prefiltering band-specific distor-tions were used.

1) Hard symmetrical clipping, with the clipping levelset so that the input signal was clipped 2 or 10% of thetime.

2) Soft symmetrical clipping, with the clipping set sothat the input signal exceeded the clipping threshold 5 or20% of the time.

3) Full-range distortion with α 0.7 or 1.3.In the second set of conditions, the distortion was

applied to the waveform at the output of one of the filters,as before, but then the distorted waveform was postfilteredusing the same filter. For example, if the distortion was

applied to the output of the filter covering the range606–1973 Hz, the distorted waveform was subsequentlybandpass filtered over the range 606–1973 before the out-puts of the different filters were recombined. Thisrestricted the distortion components to a specific fre-quency region. Such distortion would occur only rarely ina real nonlinear system, but it was used here to allow us togain some insight into the relative importance of the dis-tortion components in different frequency regions. Thepre- and postfiltering band-specific distortions were thesame as those described in 1) to 3) for prefiltering only. Inaddition, we included some distortions applied to thewide-band signal, similar to those used in experiment 1.The wide-band distortions were as follows


Fig. 2. As Fig. 1, but for music stimulus.

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1) Hard symmetrical clipping, with the clipping levelset so that the input signal was clipped 2 or 5% of thetime.

2) Soft symmetrical clipping, with the clipping set sothat the input signal exceeded the clipping threshold 5 or20% of the time.

3) Full-range distortion with α 0.5, 0.7, 1.3, and 2.We also included a condition with no distortion.

In summary, there were 24 conditions involving pre-filtering (six types of distortion applied in each of fourpassbands), 24 conditions involving pre- and postfiltering(six types of distortion applied in each of four passbands),eight conditions involving distortions applied to thebroad-band signal, and one condition with no distortion,giving a total of 57 conditions.

3.2 Subjects and ProcedureEleven normally hearing subjects were tested. None had

any history of hearing disorders and all had audiometricthresholds better than or equal to 20 dB HL in both ears atall audiometric frequencies from 250 to 8000 Hz. Theirages ranged from 20 to 27 years (mean 23, standard devi-ation 2). Subjects were paid for their participation. Theprocedure was the same as described for experiment 1.

4 RESULTS

4.1 Consistency across Sessions and SubjectsAs before, the consistency across test sessions was

assessed by calculating the mean score across subjects foreach condition and stimulus type, separately for each ses-sion, and then calculating the correlation of the scores forthe 57 conditions across sessions. The correlationsobtained in this way were 0.976 for the speech stimuli and0.966 for the music stimuli. The very high correlationsindicate a high degree of consistency of the group meansacross test sessions.

The pattern of results was also consistent across sub-jects. Correlations between individual scores and meanscores, calculated as for experiment 1, are shown in Table2. The correlations are high, indicating a high degree ofconsistency across subjects, although the consistency isnot quite as high as for experiment 1. The SD of the rat-ings across subjects for a given condition was typicallyabout 1.6 scale units (SE about 0.5 scale unit), which isslightly higher than for experiment 1. This may reflectindividual variability in the relative importance of differ-ent frequency regions.

As before, ANOVAs were conducted on the ratings withsubject and amount of distortion as factors. For the distor-tions involving filtering, the type of filtering was includedas a factor (prefiltering alone, or pre- and postfiltering)

and the center frequency of the band where the distortionwas introduced was also a factor. ANOVAs were calcu-lated separately for the speech and music stimuli. We con-sider in this section only the outcomes relating to individ-ual differences; other outcomes are discussed in thefollowing section.

For the broad-band distortions the effect of subject wassometimes significant, indicating that some subjects gavelower or higher overall ratings than others. The interactionof subject and amount of distortion was not significant inany case, indicating that the pattern of results did not dif-fer across subjects. For the distortions involving filtering,the effect of subject was sometimes significant, and therewere a few cases where subject interacted with other fac-tors, indicating a difference in the pattern of results acrosssubjects. These cases were as follows.

1) For speech stimuli with hard symmetrical clipping,there was a significant interaction of subject with type offiltering (pre or pre and post); F(10, 176) 2.8, p 0.003.

2) For speech stimuli with full-range distortion, there wasa significant interaction of subject with α, F(10, 176) 2.64, p 0.005, and of subject with band center fre-quency F(30, 176) 2.19 p < 0.001.

3) For music stimuli with hard symmetrical clipping,there was a significant interaction of subject with band cen-ter frequency, F(30, 176) 1.79 p 0.011.

4) For music stimuli with full-range distortion, there wasa significant interaction of subject with α, F(10, 176) 3.31, p < 0.001, and of subject with band center frequency,F(30, 176) 2.26, p < 0.001.

These interactions never accounted for more than 1% ofthe variance in the data, and in three out of four cases theyaccounted for less than 0.5% of the variance. As before,we conclude that the ratings are mainly determined by theamount and type of distortion in the stimuli, and that indi-vidual differences in the patterns of ratings are small.

4.2 Mean RatingsThe mean ratings for the distorted stimuli are shown in

Figs. 3–8. The ratings for the broad-band distortions(Figs. 3 and 6) are similar to those obtained in experiment1. The ANOVAs showed that ratings always decreased sig-nificantly with increasing amounts of distortion (p < 0.001in all cases). For the full-range distortion, ratingsdecreased as α was made more different from 1 (becom-ing either larger or smaller than 1). The general pattern ofthe results was similar for the speech stimuli and for themusic stimuli. For the prefiltering distortions (Figs. 4 and7) the ratings were generally lower when the distortionwas introduced into the lower frequency bands (but thedistortion was allowed to spread to other frequencies) than



Subject 1 2 3 4 5 6 7 8 9 10 11

Speech 0.92 0.91 0.92 0.94 0.92 0.92 0.94 0.96 0.93 0.96 0.91Music 0.89 0.91 0.93 0.93 0.94 0.92 0.96 0.95 0.89 0.93 0.89


when the distortion was introduced into the higher fre-quency bands. However, for the pre- and postfiltering dis-tortions (Figs. 5 and 8) the effects were much more uni-form across the different frequency bands, suggesting thatthe distortion components within each band were roughlyequally important. These patterns are revealed in theANOVAs as significant overall effects of band center fre-quency (p < 0.001 for both speech and music for all typesof distortion) and significant interactions between type offiltering (pre or pre and post) and band center frequency;the significance level was p < 0.001 for all types of dis-tortion for both speech and music. An exception to thetrend of roughly equal importance of each frequency bandfor pre- and postfiltering was for the full-range modifica-tion with α 0.7. For this case the ratings for pre- andpostfiltering were lower for the two middle bands than forthe lowest or highest bands. Post hoc tests, based onFisher’s least significant differences test, showed that themean ratings for the two middle bands were significantlylower than the mean ratings for the lowest and highestbands (p < 0.001 in all cases).

The fact that, for prefiltering distortions, the ratingswere generally lower when the distortion was introducedinto the lower frequency bands can probably be attributedto the physical effects of the distortions. The distortionsintroduced into the lower bands would have led to har-monic distortion products that covered a wide frequency

range, including the upper bands. When pre- and postfil-tering were used, the out-of-band distortion products wereremoved, and this led to higher overall ratings than forprefiltering alone, and also to more uniform ratings acrossfrequency bands.

5 PHYSICAL MEASURES OF DISTORTIONUSING MULTITONE SIGNALS

The multitone signals used here had properties similarto those described by Czerwinski et al. [8], [9], includingthe logarithmic spacing of components, as recommendedby them. However, their multitone signals had a lowestcomponent of 1000 Hz and a highest component of 10 000Hz. Such signals would not have revealed distortions insome of the conditions of experiments 2, for which thedistortion originated in the lowest frequency band.Therefore we decided to use multitone signals whosecomponents spanned the range from 50 to 15 000 Hz. Theroot-mean-square (rms) value of each multitone input sig-nal was set equal to the input level of the speech and musicsignals used in experiments 1 and 2. We used a variety ofmultitone signals, differing in their number of compo-nents, which ranged from 5 to 60. In all cases the compo-nents were uniformly spaced on a logarithmic scale overthe range 50 to 15 000 Hz. For example, for a multitonecomplex with 20 components the frequency ratio between


Fig. 3. Mean results of experiment 2 for broad-band distortions for speech stimulus. SymH—symmetrical hard clipping; SymS—sym-metrical soft clipping; FR—full-range waveform distortion. Extreme right-hand column shows mean rating for undistorted stimulus.

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Fig. 4. Mean results of experiment 2 for prefiltering distortions for speech stimulus.



Fig. 5. Mean results of experiment 2 for pre- and postfiltering distortions for speech stimulus.

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successive components was 1.35. For initial analyses theduration of each multitone signal was 1 s.

A plot of the long-term spectrum of the output of a non-linear system in response to a multitone signal gives animmediate visual indication of the extent of distortion [8],[9]. This is illustrated in Fig. 9, which is based on a 10-component multitone signal. Fig. 9 (a) shows the spectrumof the input signal, and Fig. 9 (b) shows the output of thebroad-band full-range nonlinear system from experiments1 and 2, for which the instantaneous amplitude of the sig-nal was raised to the power of 0.5. This system receivedvery low ratings for both speech and music. The severedistortion introduced by this system is readily apparent.Fig. 9 (c) shows the output of the system used in experi-ment 2 with 2% hard clipping in the highest frequencyband, using pre- and postfiltering. This system receivedhigh ratings for both speech and music. The distortionapparent in the output spectrum is correspondingly ratherlow and is restricted to high frequencies.

Although these figures are informative, it is not obvioushow to use the output spectrum to give a quantitative esti-mate of the perceived quality of the distorted signals. Oneapproach would be to calculate excitation patterns evokedin the auditory system by the input and output spectra, andto use the differences between the excitation patterns as anestimate of the perceptual difference [6]. However, thisapproach is computationally intensive. Also, an approachbased on excitation patterns would not work well in cases

where the device under test produced linear distortion(that is, the device had a nonflat frequency response) aswell as nonlinear distortion. Here we adopted a simplermethod of quantifying the differences between the inputand output spectra, but a method that is still related to thespectral resolution of the auditory system.

Initially the input and output were time aligned, to com-pensate for any time delay caused by the nonlinear pro-cessing. Both the input and output of each nonlinear sys-tem were analyzed in a series of successivenonoverlapping 30-ms frames. The power spectrum ofeach frame was determined using a 1323-point discreteFourier transform (DFT). The overall magnitude of theoutput spectrum was scaled so that the major peaks hadthe same magnitude as for the input spectrum. The bins inthe DFT were grouped into nonoverlapping frequencybands, each of which was 1 ERBN wide, where ERBNdenotes the mean equivalent rectangular bandwidth of theauditory filter for young normally hearing subjects atmoderate sound level [6], [30]. The ERBN is conceptuallysimilar to the traditional critical bandwidth [31] but differssomewhat in numerical values. The powers of the individ-ual bins within each frequency band were summed to givethe overall power in each 1-ERBN band, and the powerwas converted to decibels. For each frame the differencein level in each 1-ERBN band between the input and out-put was calculated, and the absolute value of the differ-ence was summed across bands. This gives a perceptually






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relevant measure of the difference in spectrum betweenthe input and output, which we will call the distortionscore, DS. The values of DS were averaged across all 30-ms frames to give an overall measure of distortion.

Several parameters were varied to explore their effecton the relationship between the DS values and the subjec-tive ratings. These included the number of components inthe multitone signal, the relative phases of the componentsin the multitone signal, the duration of the multitone sig-nal, and the effect of windowing the 30-ms segments prior

to calculating the DFT.For each of the multitone signals (with 5–60 compo-

nents) the DS values were calculated for each nonlinearsystem used in experiments 1 and 2, and the correlationwas calculated between the DS values and the subjectiveratings. This was done separately for the ratings of thespeech and music signals. As expected, the correlationswere always negative, as a large value of DS implies alarge amount of distortion and therefore a low rating. Forboth experiment 1 and experiment 2, the correlations


Fig. 9. (a) Spectrum of 10-component multitone signal. (b) Output spectrum of nonlinear system producing severe broad-band distor-tion. (c) Output spectrum of nonlinear system producing mild distortion at high frequencies only.

(c)

(b)

(a)

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obtained in this way were maximal for a multitone signalcontaining 10 components, and decreased slightly inabsolute value when the number of components wasdecreased to 5 or was 20 or above. Hence we decided tofocus on the results obtained using multitone signals with10 components, which gave strong negative correlationsfor both experiments. For further evaluations we used sev-eral different forms of the multitone signal, differing in the(randomly selected) starting phases of the components.We found that the starting phase had only a small effect onthe outcome, but we chose the set of phases that gave thehighest negative correlation between the subjective ratingsand the DS values. The values used are shown in Table 3.

Increasing the duration of the multitone signal beyond1 s did not increase the absolute value of the correlations,so we restricted the duration to 1 s. Windowing the 30-mssegments of the output signal prior to calculating the DFThad the effect of reducing spectral splatter from the majorcomponents of the signal (those present at the input), thusmaking it possible to measure the effects of distortion

components at lower levels than when no windowing wasused. However, we found that the windowing made theabsolute values of the correlations smaller rather thanlarger. This may have happened because distortion com-ponents at very low levels would not be perceptually rele-vant, as they would be masked by the primary componentsor would be below absolute threshold. Hence for theanalyses presented next, the segments were not windowedprior to calculating the DFT.

Fig.10 shows scatter plots of the relationship betweenthe DS values and the subjective ratings for experiment 1.The (inverse) correlation between the two quantities ishigh, at 0.98 (p < 0.001) for speech and 0.97 (p <0.001) for music. Fig. 11 shows similar scatter plots forexperiment 2. Here the scatter is greater, but the correla-tions are still reasonably high, namely 0.87 (p < 0.001)for speech and 0.80 (p < 0.001) for music. We concludethat the physical measure DS is closely related to per-ceived distortion, at least for the artificial types of distor-tion used in experiments 1 and 2.

6 VERIFICATION EXPERIMENT

6.1 StimuliTo assess whether the DS measure gave reasonable pre-

dictions of the perceived quality of signals subjected to thedistortion produced by real transducers, we conducted athird perceptual experiment. The same speech and musicsignals as before were used as input to the nonlinear sys-tems under test. A few of the nonlinear systems used ear-lier were included, namely:

1) Hard symmetrical clipping of the broad-band signal,with the clipping level set so that the input signal wasclipped 2 or 5 % of the time.

2) Soft symmetrical clipping of the broad-band signal,with the clipping set so that the input signal exceeded theclipping threshold 5 or 20 % of the time.


Fig. 10. Scatter plots of mean subjective ratings form experiment 1, plotted against distortion measure DS. (a) Results for speech stim-ulus. (b) Results for music stimulus. Each point represents a specific form of broad-band distortion.

(a) (b)

Table 3. Frequencies and starting phases of10-component multitone signal that gave thehighest (negative) correlation between dis-tortion measure DS and ratings obtained.

Hz rad

50 2.54994 5.878178 5.761335 2.578631 5.6151189 0.3642241 2.2174223 5.1097959 0.06215000 0.873


3) Full-range distortion of the broad-band signal with 0.5, 0.7, 1.3, and 2.

4) Prefiltering band-specific distortion with 0.7 and1.3 in the bands 606–1973 Hz and 1973–5583 Hz.

The other nonlinear systems involved four differentcompact electrodynamic transducers (13–20 mm in diam-eter) mounted in a variety of acoustic structures, selectedto be representative of earpieces and so-called integratedhands-free designs often encountered in telecommunica-tions terminal devices or accessories. Both commercialproducts and acoustic mockups were used. These includedclosed-box and ported acoustics, with a range of back vol-umes (1–5 cm3), a number of different front volumes, anddifferent sound port arrangements. The total number ofsystems used was 15.

The test signals (sampling rate 41 000 Hz) were fed tothe test systems from a PC via a Lexicon CD-2, acting asa DAC, and via a Lab Gruppen LAB300 amplifier. Eachtransducer was driven at two power levels, one of whichwas below the official rated power handling of the trans-ducer and the other of which was 7–20 dB above the ratedpower. This was done to ensure the generation of bothweak and strong nonlinearities, without causing perma-nent damage to the transducers. The output of each trans-ducer was measured in the free field using a G.R.A.S.40AF 0.5-in free-field microphone, a G.R.A.S. 2AA pre-amplifier, and a Brüel & Kjær Nexus conditioning ampli-fier. The microphone was located 250 mm from the soundoutlet of the device or on the axis of the loudspeaker,depending on the test configuration. The measured signalwas recorded to the PC hard disk (sampling rate 44 100Hz) via a Tascam DA30 (acting as ADC) and an RMEDigital 96/8 sound card.

In summary, there were eight conditions involving arti-ficial distortion of the broad-band signal, four conditionsinvolving artificial distortion with prefiltering (two bandstimes two values of α), and 30 conditions involving real

transducers (15 systems, each driven at two levels). Wealso included a condition with no distortion. The totalnumber of conditions was 43.

One problem in using real transducers is that they intro-duce linear distortion (frequency response irregularities)as well as nonlinear distortion. Our interest in the presentstudy was to characterize the perceptual effects of the non-linear distortion without any confounding effect of lineardistortion. Therefore the recorded outputs of the real trans-ducers were each digitally filtered so that the long-termspectrum of the output matched that of the input as closelyas possible. In practice this could not be done over a verywide frequency range, as some of the transducers showeda considerable rolloff in their amplitudes response at lowfrequencies. Therefore to match the amplitude–frequencyresponse of all systems as closely as possible, all stimuliwere bandpass filtered between 301 and 15 900 Hz. Thiswas done both for the stimuli recorded via real transduc-ers and for those generated using artificial distortion.

6.2 Subjects and ProcedureNine normally hearing subjects were tested. None had

any history of hearing disorders and all had audiometricthresholds better than or equal to 20 dB HL in both ears atall audiometric frequencies from 250 to 8000 Hz. Theirages ranged from 20 to 31 years (mean 27, standard devi-ation 4). Subjects were paid for their participation. Theprocedure was the same as described for experiment 1.

6.3 Consistency across Sessions and Subjects As before, the consistency across test sessions was

assessed by calculating the mean score across subjects foreach condition and stimulus type, separately for each ses-sion, and then calculating the correlation of the scores forthe 43 conditions across sessions. The correlationsobtained in this way were 0.94 for the speech stimuli and0.91 for the music stimuli. The high correlations indicate


Fig. 11. As Fig. 10, but for ratings from experiment 2, which include distortions with pre- and postfiltering. (a) Speech test. (b) Music test.

(a) (b)

TAN ET AL. PAPERS

a high degree of consistency of the group means acrosstest sessions.

The pattern of results was reasonably consistent acrosssubjects. Correlations between individual scores and meanscores, calculated as for experiment 1, are shown in Table4. The correlations range from 0.75 to 0.94, indicatinggood consistency across subjects, although the consis-tency is not quite as high as for experiment 1. The SD ofthe ratings across subjects for a given condition was typi-cally about 1.6 scale units (SE about 0.5 scale units),which is slightly higher than for experiment 1, but similarto experiment 2.

As before, ANOVAs were conducted on the ratings withsubject and amounts of distortion as factors. This wasdone only for the artificial distortions. For the distortionsinvolving prefiltering, the center frequency of the bandwhere the distortion was introduced was also a factor.ANOVAs were calculated separately for the speech andmusic stimuli. The effect of the amount of distortion wasalways highly significant (p < 0.001). For the broad-banddistortions, the effect of subject was sometimes significant,indicating that some subjects gave lower or higher overallratings than others. The interaction of subject and value ofα was significant for speech, F(30, 44) 1.99, p 0.018,and for music, F(30, 44) 1.97, p 0.02. However, inboth cases the interaction accounted for less than 1% ofthe variance in the data. For the distortions involving pre-filtering, the interaction of subject and value of α was sig-nificant for speech, F(10, 44) 5.59, p < 0.001, and formusic, F(10, 44) 6.48, p < 0.001, but in both cases theinteraction accounted for less than 2% of the variance inthe data. We conclude, as before, that the ratings aremainly determined by the amount and type of distortion inthe stimuli, and that individual differences in the patternsof ratings are small.

6.4 Comparison of Obtained Ratings andDistortion Score

As mentioned earlier, all stimuli in this experimentwere bandpass filtered between 301 and 15 900 Hz (andspectrally shaped where appropriate), so as to remove asfar as possible differences in overall spectral shape of theoutputs for the differently distorted signals. This was doneto allow us to isolate the perceptual effects of nonlineardistortion by equating linear distortion across conditions.In our previous analyses using the multitone test signal,that signal covered a wide frequency range, from 50 to15 000 Hz. Such a signal would have been inappropriateto use here, since the input would have contained fre-quency components that were not present in the output ofthe systems under test. To avoid this problem, the inputmultitone signal was bandpass filtered between 301 and

15 900 Hz, in the same way as the stimuli were bandpassfiltered in the experiment. Otherwise the calculation of theDS score was done in the same way as before.

Fig. 12 compares the mean ratings for the different sys-tems with the DS score obtained using the multitone sig-nal as input to the systems. There is a moderately strongrelationship between the ratings and the DS values. The


Fig. 12. As Fig. 10, but for ratings from experiment 3, whichinclude distortions introduced by real transducers. (a) Music test.(b) speech test. Artificial distortions; real distortions.

(b)

(a)


Subject 1 2 3 4 5 6 7 8 9

Speech 0.83 0.85 0.88 0.88 0.80 0.83 0.92 0.93 0.85Music 0.77 0.94 0.90 0.84 0.91 0.75 0.81 0.92 0.86


correlations is 0.64 (p < 0.001) for speech and 0.595(p < 0.001) for music. It is clear, however, that there israther a lot of scatter. It appears that the relationship ofthe subjective ratings to the DS scores is somewhat dif-ferent for the artificial distortions (circles) and the realdistortions (asterisks). This was confirmed by calculat-ing the correlation between the ratings and the DS scoresseparately for the artificial and real distortions. The cor-relations for the artificial distortions were –0.91 (p <0.001) for speech and 0.86 (p < 0.005) for music. Thecorrelations for real distortions were 0.60 (p < 0.005)for speech and 0.67 (p < 0.005) for music. Evidentlythe DS measure is more closely related to the subjectiveratings for the well-defined artificial distortions than forthe more complex real distortions.

It is noteworthy that the mean scores for the undistortedstimuli were relatively high, at 7.94 and 7.22 for speechand music, respectively, even though those stimuli werebandpass filtered between 301 and 15 900 Hz. In our pre-vious study of the perceptual effects of linear distortion[10] we found that high-pass filtering at 313 Hz led tomean ratings of 2.1 for speech and 2.2 for music. Thelarge difference in ratings across the two experiments indi-cates that subjects adjust their criteria depending on therange and type of stimuli presented. In experiment 3 allstimuli lacked frequency components below 301 Hz, andhence sounded rather tinny. However, the stimuli withoutnonlinear distortion clearly sounded better than the stim-uli with strong nonlinear distortions, and the ratings givenby the subjects reflected this. It is likely that the examplestimuli played before the experiment proper contributed tothe adjustment of the criteria of the subjects, and encour-aged them to use much of the available response range.Although subjects clearly did change their criteria acrossexperiments, the ratings given to the bandpass filteredundistorted stimuli in experiment 3 were lower than the rat-ings given to the broad-band stimuli with little or no distor-tion in experiment 1 and 2, which were typically about 9.

7 SUMMARY AND CONCLUSIONS

We have examined the effects of various types of non-linear distortions on the perceived quality of speech andmusic signals. Subjects were presented with a series ofdistorted signals, with the different types of distortion pre-sented in a randomized order, and were required to rate theperceived amount of distortion on a scale from 1 to 10,where 1 corresponds to most distorted and 10 correspondsto least distorted. The results for all experiments werehighly consistent across subjects and test sessions. Theratings are largely determined by the amount and nature ofthe distortion in the signals, individual differences makingonly a small contribution to the variance in the ratings.Center clipping and soft clipping had only small effects onthe ratings, whereas hard clipping and the full-range dis-tortions had large effects. When the frequency compo-nents introduced by the distortion were limited to a spe-cific frequency range (defined in ERBN), all of the fourranges tested were approximately equal in importance inaffecting perceived distortion.

The subjective ratings obtained from the first twoexperiments, which used various artificial forms of distor-tion, were compared to physical measures of distortionbased on multitone test signals. A distortion measure DSderived from the output spectrum of each nonlinear sys-tem in response to a 10-component multitone signal gavehigh correlations with the subjective ratings. The correla-tions were negative because high ratings were associatedwith low values of DS. For experiment 1 the correlationswere 0.98 and 0.97 for speech and music, respectively.For experiment 2 the correlations were 0.87 and 0.80for speech and music, respectively.

A further experiment was conducted using stimuli forwhich nonlinear distortion was introduced by recording theoutputs of real transducers. The output signals were digitallyfiltered to reduce irregularities in amplitude–frequencyresponse as far as possible. The results showed reasonablystrong negative correlations between the subjective ratingsand the objective measure DS; for the stimuli recordedthrough real transducers, the correlations were 0.60 and0.67 for speech and music, respectively. However, thecorrelations were not as high as for the artificial distor-tions. We conclude that an objective measure of nonlineardistortion based on the use of a multitone signal can pre-dict reasonably well the perceptual effects of nonlineardistortion.

8 ACKNOWLEDGEMENT

This work was supported by Nokia Research Center(Finland). The authors wish to thank Kalle Koivuniemi(Nokia Research Center) for performing the acousticalmeasurements of the real transducers. They also thankTom Baer, Brian Glasberg, and Michael Stone for theirassistance with various aspects of this work, as well asRosalie Uchanski and two anonymous reviewers for help-ful comments on an earlier version of this paper.

9 REFERENCES

[1] R. Plomp, “Timbre as a Multidimensional Attributeof Complex Tones,” in Frequency Analysis and PeriodicityDetection in Hearing, R. Plomp and G. F. Smoorenburg,Eds. (Sijthoff, Leiden, The Netherlands, 1970).

[2] R. Plomp, Aspects of Tone Sensation (Academic,London, 1976).

[3] A. Gabrielsson, B. N. Schenkman, and B.Hagerman, “The Effects of Different FrequencyResponses on Sound Quality Judgments and SpeechIntelligibility,” J. Speech Hear. Res., vol. 31, pp. 166–177(1988).

[4] A. Gabrielsson, B. Hagerman, T. Bech-Kristensen,and G. Lundberg, “Perceived Sound Quality ofReproductions with Different Frequency Responses andSound Levels,” J. Acoust. Soc. Am., vol. 88, pp.1359–1366 (1990).

[5] A. Gabrielsson, B. Lindström, and O. Till,“Loudspeaker Frequency Response and Perceived SoundQuality,” J. Acout. Soc. Am., vol. 90, pp.707–719 (1991).

[6] B. C. J. Moore, An Introduction to the Psycho-


THE AUTHORS

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logy of Hearing, 5th ed. (Academic, San Diego, CA,2003).

[7] A. Gabrielsson, P. O. Nyberg, H. Sjögren, and L.Svensson, “Detection of Amplitude Distortion by NormalHearing and Hearing Impaired Subjects,” KarolinskaInstitute, Tech. Audiology, vol. TA 83, pp. 1-20 (1976).

[8] E. Czerwinski, A. Voishvillo, S. Alexandrov, and A.Terekhov, “Multitone Testing of Sound SystemComponents—Some Results and Conclusions, Part 1:History and Theory,” J. Audio Eng. Soc., vol 49, pp.1011–1042 (2001 Nov.).

[9] E. Czerwinski, A. Voishvillo, S. Alexandrov, and A.Terekhov, “Multitone Testing of Sound SystemComponents—Some Results and Conclusions, Part 2:Modeling and Application,” J. Audio Eng. Soc., vol 49, pp.1181–1192 (2001 Dec.).

[10] B. C. J. Moore and C. T. Tan, “PerceivedNaturalness of Spectrally Distorted Speech and Music,” J.Acoust. Soc. Am., vol. 114, pp. 408–419 (2003).

[11] ANSA S3.22-1996, “Specification of Hearing AidCharacteristics,” American National Standards Institute,New York (1996).

[12] J. M. Risch, “A New Class of In-Band MultitoneTest Signals,” presented at the 105th Convention of theAudio Engineering Society, J. Audio Eng. Soc.(Abstracts), vol. 46, p. 1037 (1998 Nov.), preprint 4803.

[13] J. M. Kates, “A Test Suite for Hearing AidEvaluation,” J. Rehab. Res. Devel., vol. 27, pp. 255–278(1990).

[14] D. A. Preves, “Expressing Hearing Aid Noise andDistortion with Coherence Measurements,” Asha, vol. 32,pp. 56–59 (1990).

[15] O. Dyrlund, “Coherence Measurements inHearing Instruments, Using Different Broad-BandSignals,” Scand. Audiol., vol. 21, pp. 73–78 (1992).

[16] J. M. Kates, “On Using Coherence to MeasureDistortion in Hearing Aids,” J. Acoust. Soc. Am., vol. 91,pp. 2236–2244 (1992).

[17] J. M. Kates and L. Kozma-Spytek, “QualityRatings for Frequency-Shaped Peak-Clipped Speech,” J.Acoust. Soc. Am., vol. 95, pp. 3586–3594 (1994).

[18] J. M. Kates, “Cross-Correlation Procedures forMeasuring Noise and Distortion in AGC Hearing Aids,” J.Acout. Soc. Am., vol. 107, pp. 3407–3414 (2000).

[19] ITU-R BS. 1387.1, “Method for ObjectiveMeasurements of Perceived Audio Quality,” InternationalTelecommunications Union, Geneva, Switzerland, pp.1–100.

[20] ITU-T P.862, “Perceptual Evaluation of SpeechQuality (PESQ): An Objective Method for End-to-EndSpeech Quality Assessment of Narrow-Band TelephoneNetworks and Codecs,” International TelecommunicationsUnion, Geneva, Switzerland, pp. 1–24.

[21] M. D. Burkhard and R. M. Sachs, “Anthropome-tric Manikin for Acoustic Research,” J. Acoust. Soc. Am.,vol. 58, pp. 214–222 (1975).

[22] E. A. G. Shaw, “Transformation of Sound PressureLevel from the Free Field to the Eardrum in the HorizontalPlane,” J. Acoust. Soc. Am., vol. 56, pp. 1848–1861(1974).

[23] G. Kuhn, “The Pressure Transformation from aDiffuse Field to the External Ear and to the Body andHead Surface,” J. Acoust. Soc. Am., vol. 65, pp. 991–1000(1979).

[24] M. C. Killion, E. H. Berger, and R. A. Nuss,“Diffuse Field Response of the Ear,” J. Acoust. Soc. Am.,vol. 81, p. S75 (1987).

[25] J. E. Jacobs and P. Wittman, “Psychoacoustics, theDetermining Factor in Stereo Disc Distortion,” J. Acoust.Soc. Am., vol. 12, pp. 115–123 (1964).

[26] T. Letowski, “Difference Limen for NonlinearDistortion in Sine Signals and Musical Sounds,” Acustica,vol. 34, pp. 106–110 (1975).

[27] B. C. J. Moore, B. R. Glasberg, and T. Baer, “AModel for the Prediction of Thresholds, Loudness, andPartial Loudness,” J. Audio Eng. Soc., vol. 45, pp.224–240 (1997 Apr.).

[28] E. Larsen and R. M. Aarts, “Reproducing Low-Pitched Signals through Small Loudspeakers,” J. AudioEng. Soc., vol. 50, pp. 147–164 (2002 Mar.).

[29] E. C. Poulton, “Models for the Biases in Judging Sen-sory Magnitude,” Psych. Bull., vol. 86, pp. 777–803 (1979).

[30] B. R. Glasberg and B. C. J. Moore, “Derivation ofAuditory Filter Shapes from Notched-Noise Data,” Hear.Res., vol. 47, pp. 103–138 (1990).

[31] E. Zwicker, “Subdivision of the Audible Fre-quency Range into Critical Bands (Frequenzgruppen),” J.Acoust. Soc. Am., vol. 33, p. 248 (1961).


C. T. Tan B. C. J. Moore N. Zacharov



Chin-Tuan Tan received B.E., M.E., and Ph.D. degreesin electrical and electronic engineering from the NanyangTechnological University (Singapore) in 1992, 1996, and2000, respectively. His doctorate was on "Zero-Crossing-Based Compression Hearing Aids." He then joined BrianMoore's Hearing Group and now works as a postdoctoralresearch associate in the Department of ExperimentalPsychology, University of Cambridge. His presentresearch project focuses on the perception of distortion inspeech and music. His research interests include speechand auditory processing, digital signal processing, andhearing aids. He plays basketball and sings in the WolfsonCollege Choir.

Brian Moore is a professor of auditory perception at theUniversity of Cambridge, UK. He is a fellow of the RoyalSociety, the Academy of Medical Sciences, and theAcoustical Society of America; and an honorary fellow ofthe Belgian Society of Audiology and the British Societyof Hearing Aid Audiologists. He is president of theAssociation of Independent Hearing HealthcareProfessionals (UK). He is a member of the EditorialBoards of Hearing Research, The International Journal ofAudiology, and Audiology and Neuro-Otology. He is aconsultant for several USA and European companies. Hehas written or edited 12 books and over 370 scientificpapers and book chapters. He was recently awarded theAcoustical Society of America’s Silver Medal in physio-

logical and psychological acoustics. He is wine steward ofWolfson College, Cambridge.

Nick Zacharov was born in London in 1969. Heobtained a Bachelor degree in Electroacoustics fromSalford University, UK, and Master of Science and Doctorof Science degrees in technology from the HelsinkiUniversity of Technology, Acoustics and Audio SignalProcessing in 1997 and 2002, respectively. After complet-ing a one-year training period while in the UK with theFinnish loudspeaker manufacturer, Genelec, Dr. Zacharovreturned to Finland as a design engineer with Genelec forover two years. He is currently working for NokiaResearch Center in Tampere, Finland, as a principal sci-entist in the field of audio quality assessment. He is also achartered engineer. His present research interests includespatial sound reproduction systems, audio quality, andperceptual evaluation methods.

Dr. Zacharov is a member of the Institute of Acousticsand the Acoustical Society of America and a vice-chairmanof the AES Finnish Section. He was also the vice-chair-man of the AES 16th International Conference on SpatialSound Reproduction, 1999; co-chairman of the AES22nd International Conference on Virtual, Synthetic andEntertainment Audio, 2002; and an AES governor. He hasa number of publications and patents in the field of audio.He enjoys photography, cookery, downhill skiing, travel,and audio.

ENGINEERING REPORTS

0 INTRODUCTION

Bit-rate reduction audio coding has found extensive usein the transmission and storage of high-quality audio pro-grams. Typical applications include digital film sound, dig-ital television sound, DVDs, laser discs, digital radio, andpoint-to-point audio links. In these applications, high cod-ing efficiency, inexpensive decoding for consumer applica-tions, and ease of use have often been required. Recentlystereo sound applications have increasingly been sup-planted with 5.1 (or larger) channel configurations that areoften associated with video programs. The term 5.1 chan-nels indicates the use of five channels of full-bandwidthaudio plus a low-frequency effects (LFE) channel, desig-nated as .1.

The move to 5.1 or larger channel sound has the poten-tial of greatly enhancing sound reproduction and the con-sumer’s experience. Unfortunately it comes at the cost ofrequiring a significant change in the sound distributionenvironment. This is true because much of the audiodelivery means are only capable for two- or four-channeltransport. The larger multichannel audio configurations( 5.1 channels) also require significantly larger trans-missions date rates as the number of channels grows. Forexample, current discussions regarding audio for emerg-ing digital cinema applications commonly discuss the useof up to 16 channels of discrete audio.

As multichannel audio and video content become more

commonly coupled, audio editing and switching have alsobecome more difficult because the association with videoimplies that it is desirable for the audio distributionmethod to be more "videolike" in its framing and struc-ture. The different inherent time latencies and time mis-matches between the sound and pictures framing struc-tures exhibited by various coding algorithms makeaudio–video distribution even more problematic.

This engineering report describes some of the signifi-cant design features used to create a new coding systemadapted for audio–video distribution applications, basedon the Dolby E broadcast distribution coding system (seeFielder and Todd [1]). This new coding system is designedto independently code up to eight channels of audio fortransport on a standard two-channel digital-audio inter-face, the AES3 standard [2]. The new coding system hasalso been designed to independently code and transportany number of audio channels that fit within the allowablebandwidth of the selected transport mechanism. This pro-vides additional flexibility and capability for the storageand transmission of many channels of high-quality,reduced bit-rate audio using systems that do not have thebandwidth limitations of AES3, such as a digital cinemaserver. The compressed audio is enclosed and formatted sothat it is compatible with a wide variety of video formats,easy to edit in the video distribution environment, andcapable of providing excellent sound quality after morethan three tandem coding generations. The system isintrinsically self-editable in the encoded domain andlocked to the associated video signal.

In addition to the new coding system, this reportdescribes a solution to the problem of coding the noninte-


Ultra-High Quality Video FrameSynchronous Audio Coding*

MICHAEL J. SMITHERS, AES Member, BRETT G. CROCKETT, AES Member,AND LOUIS D. FIELDER, AES Fellow

Dolby Laboratories, San Francisco, CA 94103, USA

Two methods of coding and delivering ultra-high-quality audio are presented. Bothmethods are video frame synchronous and editable at common video frame rates (23.98, 24,25, 29.97, and 30 frames per second) without the use of sample-rate converters. The first isan ultra-high-quality audio coder that exceeds 4.8 on the ITU-R five-point audio impairmentscale at a bit rate of 256 kbit/s per channel and at up to three generations ofencoding/decoding. The second is an enhanced method of video frame synchronous PCMpacking. Specifically the problem of transmitting 48-kHz audio in 29.97-Hz frames isexamined.

*Presented at the 114th Convention of the Audio EngineeringSociety, Amsterdam, The Netherlands, 2003 March 22–25;revised 2003 September 4.

ENGINEERING REPORTS VIDEO FRAME SYNCHRONOUS AUDIO CODING

ger sample frame length associated with the 29.97-Hzvideo frame rate, and subsequently a method of packingPCM in synchrony with video frames.

1 BASIC CODING SYSTEM

The new audio coding system is a perceptually based,adaptive transform coding system based on the Dolby Edistribution coder. Similar to Dolby E, the new coderorganizes the encoded audio into frames equal in length(time) to a video picture frame. Unlike Dolby E, the newaudio coder does not make use of sample-rate converters toprovide a fixed number of audio samples per frame for thesupported frame rates. Instead, the new audio coder usesvarying transform lengths for the different frame rates.

When being used in the AES3 transport mode, inputaudio of up to eight channels of 24-bit PCM at a 48-kHzsample rate is encoded using the appropriate transformlength for the selected video frame rate, and then sent outin a burst mode for transport on an AES3 interface at asample rate of 48 kHz.

Since the AES3 interface allows for the transport of twochannels of 24-bit audio data words at a 48-kHz samplerate, this capability is used to transport the encoded audiodata at a fixed rate of 2304 kbit/s. A fixed channel capac-ity of 256 kbit/s per full-bandwidth channel is used withadditional data available for metadata. The new codingsystem allocates 26 kbit/s for the low frequency effects(LFE) channel and 128 kbit/s for half-bandwidth, voice-grade narration channels. The high rate of 256 kbit/s forfull-bandwidth channels, compared to 64–128 kbit/sfound in broadcast applications, allows multiple tandemoperations with very high quality.

For higher bandwidth, non-AES3 transport methods,the data rates for full-bandwidth, LFE, and narration chan-nels remain the same. Therefore the maximum number ofaudio channels that can be stored and transmitted is lim-ited only to the data rate provided by the selected storageand transmission scheme. Figs. 1 and 2 show block dia-grams of the encoder and decoder structures, respectively.

1.1 Filterbank, Quantization, Bit AllocationThe coding process is performed independently for each

channel, with each channel utilizing a predeterminedamount of the available data rate depending on the channeltype (full bandwidth, LFE, or narration) as discussed pre-viously. As shown in Fig. 1, input audio signals are codedby a filter bank that is a frame-editable adaptation of themodified discrete cosine transform (MDCT) (Princen andBradley [3]). The MDCT provides for a critically sampledfilter bank via the use of a technique of time-domain aliascancellation (TDAC) (similar work in lapped transformswas also conducted by Malvar [4]). Application of theproperties of TDAC permits the development of a codingsystem suitable for editing and switching in the encodeddata domain.

The transform lengths vary between 256 samples forshort, 512 samples for bridge, and 2048 or 2304 samplesfor long transform conditions (with the long transformlength being dependent on the frame rate). The maximumtransform lengths of 2048 or 2304 samples for the longtransform are selected as best for steady-state conditionsand reduced to 256 samples under transient signal condi-tions identified by the block switch control module.

The transform coefficients from the filter bank aregrouped into frequency bands that approximate auditorycritical bands (Moore and Glasberg [5]) to perform thebit-allocation and quantization processes. Each band isrepresented by a single exponent value and a group ofcompressed transform coefficient values. The exponentvalue represents the maximum of all the transform coeffi-cient magnitudes in a given band quantized to an accuracyof 3 dB. In the algorithm’s frequency banding portion, thetransform coefficients are scaled up in value by dividingby the level represented by the exponent to form com-pressed audio words called mantissas. These mantissas arethen quantized to a level of accuracy determined by thebit-allocation process.

Exponents representing the spectral characteristics ofthe input signal, are used to derive the appropriate maskingcurve, and thus determine the accuracy of each of the man-tissas. Both the encoder and the decoder, as shown in Figs.1 and 2, use the same exponent-driven core bit-allocationprocess, a signal-to-noise offset word, and additional con-trol parameters in a manner similar to AC-3, more com-


Fig. 1. Encoder structure.

Data

Control

Mantissas

Filter Bank

Exponents

Quantizer

NoiselessCoding (GAQ)

RateControl

BitstreamMultiplex

PerceptualModel

Input Time Signal

CodedAudioStream

Iteration Loop

Block Switch Control

Bit Alloc.

Fig. 2. Decoder structure.

Data

Control

Mantissas

Filter Bank

Exponents

BitstreamDe-

Multiplex

PerceptualModel

Output Time Signal

CodedAudioStream

Inv. QuantizerNoiseless

Coding (GAQ)

Bit Alloc.

SMITHERS ET AL. ENGINEERING REPORTS

monly known as Dolby Digital. See Fielder et al. [6] forfurther details.

Mantissa quantization is performed using a processcalled gain adaptive quantization which improves codingefficiency over linear quantization. This increased codingefficiency is obtained by taking advantage of the non-uni-form probability density function for the mantissas in amanner similar to Huffman coding, but with a lower com-putational cost. Details of this quantization method arediscussed in Truman et al. [7]. This technique provides anapproximately 23% improvement in coding efficiencyover conventional linear quantization for difficult to codesignals.

2 VIDEO SYNCHRONOUS FRAME STRUCTURE

The requirement that the encoded audio be switchedand edited along with the video signal was an importantfactor in the design of the new low-bit-rate coder. Videosignals differ from audio ones in that their minimum tem-poral resolution is much lower. Video time intervals aregreater than or equal to 1/60 second, where as PCM audiohas a minimum resolution of approximately 21µs.

This examination focuses on applications with videoframe rates of 30 Hz and below. Since video must exist asan integer number of frames or fields, the editing of anaudio–video pair must be done at a video frame time res-olution or a multiple of it. The edit or switch point mustalso coincide with an audio frame interval for high-qualitysound applications because complete and uncorruptedframes of encoded audio are required for satisfactoryaudio performance. If an edit or switch occurs within acoded audio frame, it is destroyed and an audio muteoccurs. Encoded audio presents an additional problem inthat encoded frame intervals are generally much greater21 µs and are different in size than the video counterparts.

2.1 Editing Resolution in the Audio–VideoEnvironment

Table 1 shows the characteristic time intervals for 48-kHzsample-rate digital audio and a number of bit-rate reduc-tion audio coding systems in widespread use today. Theaudio coding systems displayed are AC-3 (Fielder et al.[6]), MPEG layer 1, layer 2, layer 3 (Brandenburg et al.[8]), and MPEG AAC (Bosi et al. [9]). Table 2 shows thecharacteristic time intervals for the common video framerates at 30 Hz and below.

A comparison of Tables 1 and 2 shows a basic incom-patibility between the frame intervals for conventional

audio coding and those of video formats because of theirdifferent values and the fact that they are generally notsimple multiples of each other. Even 48-kHz sample rateaudio and 29.97-Hz NTSC video are not simply related,making conventional audio editing at video frame inter-vals problematic because NTSC video frames are not syn-chronous with audio samples.

If the constraint that audio and video frames must coin-cide at edit or switch points is followed, splicing must beperformed using significantly longer intervals than a sin-gle video frame. This makes typical audio coding systemsimpractical if the video and audio are treated together. ThePAL video format is more compatible with audio coding,but editing and switching are still not generally possiblewith single-frame interval resolution.

Decoding to PCM and editing via PCM operationsmakes editing practical at a fine enough time resolutionbut its use requires the transport of uncompressed multi-channel audio in parts of the audio distribution chain or anencode/decode generation every time an edit or switchpoint exits (and still does not address the noninteger num-ber of PCM samples required for the NTSC 29.97-Hzcase).

2.2 Synchrony to Video Framing Intervalsthrough Adaptive Frame Lengths

A better audio coding system design has frame lengthsequal to and synchronous with video frames so that editsand switches occur at correct positions relative to thevideo frame, which ensures that the encoded audio framesare not corrupted. The accommodation of many videostandards, plus the problem of the noninteger relation-ship between 29.97-Hz NTSC video frames and 48-kHzsample-rate audio must be solved to create a practicalapplication of this idea.

A video frame synchronous approach to audio coding ispractically implemented via the use of coded audio framesthat have audio samples related to the video frame rate. Inthis case the number of audio samples coded per audioframe is greater than the number of 48-kHz PCM samplesthat are contained in the same amount of time encom-passed by the video frame. The number of PCM samplesthat are contained in each video frame rate are also shownin Table 2.

Previously the Dolby E coding system used fixed audiocoding transform sizes for each frame rate. This was madepossible by the use of internal sample rate converters thatcreated a fixed number of PCM samples (1792 samples)


Table 1. Time Resolution for typical audio signals.

Frame Size@ 48 kHz Time

Audio Encoding (samples) Resolution

PCM 1 20.8 µsAC-3 1536 32 ms MPEG layers 1–3 1152 24 msMPEG AAC 1024 21.33 ms

Table 2. Frame sizes and time resolutions for typical video signals.

Frame Frame Size TimeRate @ 48 kHz Resolution

Video Format (Hz) (samples) (ms)

DTV interlaced 30 1600 33.33NTSC interlaced 29.97 1601.6 33.37 PAL 25 1920 40Film 24 2000 41.6723.98-Hz film 23.98 2002 41.71


for each video frame. This resulted in an internal samplerate that was 12% to 10.5% relative to 48 kHz. Thenew coding system described here bypasses the use ofsample-rate converters and any subsequent impact onaudio quality by dynamically changing the audio coder'stransform length based on the video frame rate. Thedetails of the adaptive transform method are presented inSection 4.

3 DESIGNED FOR EDITING

Once the encoded audio frames are aligned with thevideo frames, this type of transform-based coding systemwould seem ideal for good sounding splices when bitstreams are concatenated because of the overlap-windowand window-overlap-add processes used in the encoderand decoder, respectively. This would seem to be truebecause the data in each transform block of the encodedaudio must mesh smoothly for correct coder operation.

Two problems still arise even if the transform blockframing in aligned with the video frames. If the decoderreceives a sequence of frames different from those pro-duced by an encoder, time-domain aliases will be presentand may produce audible problems. Also, the crossfadeshape must change during splice conditions to maximizethe sound quality.

3.1 Elimination of Time Aliases at FrameBoundaries

The MDCT filter bank obtains its critically samplednature because time-domain aliases are canceled fromblock to block during the decoding process. When two bitstreams are concatenated, this time-domain alias processbreaks down because switch transitions juxtapose blockswith time aliases that do not cancel. The presence of thetime alias product modifies the splice behavior in such away that it sounds more "thumpy" or abrupt.Consequently splice performance is improved signifi-cantly if the time alias products are removed.

The removal of time aliases in these regions (via time-domainaliasing cancellation, or TDAC) is accomplished by theuse of the MDCT, as shown in Eq. (1), with speciallymodified phase terms and new windows with zero-valued

segments of lengths equal to the desired alias-free region.The direct-form forward transform equation is given by

,

cosπ

X kN

x n w nN

k n n

kN

2 2

2

1

02

n

N

0

1

0

#

!^ ^ ^ e _h h h o i

R

T

SSS

V

X

WWW

(1)

wheren sample numberk frequency bin number

x(n) input PCM sequencew(n) window sequenceX(k) output transform coefficient sequence

N transform lengthn0 time alias reflection phase term.

Conventional MDCT’s use a phase term value of (N/4 1/2), whereas alias-free transforms use values of (N 1)/2 and 1/2, at the beginning and at the end of the framerespectively. These values ensure that the combinationwith the appropriate window results in an alias-free regionsuitable for frame splices. The shape of the long windowfor the 2048 long transform is shown in Fig. 3. The 2304transform has a similar window shape. The shapes of thestart and stop windows are shown in Fig. 4.

Each of the long, start, and stop windows is composed ofthree regions: region 1, a zero-valued region; region 2, aconventional TDAC region; and region 3, a zero aliasregion. The transform phase term n0 is set to position thetime aliases so that aliases from region 1 reflect to region 3,and vice versa. This eliminates alias components in region3 because a zero-valued signal (forced by the zero-valuedwindow) has zero aliases. Region 1 has no aliases becausethe window sets the signal to zero. Region 2 has conven-tional MDCT time alias properties, which allows the com-bination of this transform-window pair with conventionalMDCTs.

The length of the alias-free transform is larger than aconventional MDCT due to the addition of region 1.Therefore the removal of aliases comes at the cost of anincreased number of transform coefficients. This increaseis M/2 transform coefficients over and above the (N


Fig. 3. Long window design (2048 transform).

0 256 512 768 1,024 1,280 1,536 1,792 2,048

1

0

no time aliases

Gain

standardTDAC

Region 3Region 2no time aliases

Time (samples)

Region 1


M)/2 coefficients required by the conventional MDCT.Although the window shape for region 2 is subject to theconventional MDCT constraints, the window shape inregion 1is less constrained since there are no time aliasesto cancel, only the need for the frame to possess thedesired gain as a function of time.

The use of the alias-free transform-window pairs at theframe boundaries allows the frames to combine smoothlywhen decoded in any order. In addition, the elimination oftime aliases in the frame output allows for additional win-dow shape flexibility. A frame can be reshaped to allowfor a larger frame overlap than implied by the length of thetransform blocks used internally within a frame withoutthe introduction of time aliases. This flexibility is used toprovide a (frame-rate-dependent) 302- to 446-sample over-lap, independent of whether start, stop, or long transformblocks are used at the frame (see Table 3). Since the longtransform-window pairs provide a 302- to 446-sampleoverlap, this reshaping process alters frames containing

start or stop transform blocks. This rewindowing functionis defined by the equation

.rewindow functionoriginal frame shape

desired shape (2)

This flexibility will be shown later as also being usefulwhen modifying frame overlaps to produce better soundingsplices.

3.2 Window Design ConsiderationsTypically MDCT audio coders use either sine-function

based or Kaiser–Bessel-Derived (KBD) window functions,as described by Bosi et al. [9]. The KBD window startswith the conventional Kaiser–Bessel window, as definedby Harris [10], and is converted to a window that auto-matically satisfies the window-overlap-add constraints ofthe MDCT filter bank. The KBD window’s flexibility canvary the characteristics of the filter-bank selectivity, so


Fig. 4. (a) Alias-free start window. (b) Alias-free stop window.

(b)

2048

1

0

Gain

plus zero

Time (samples)

NM M

specialwindow

230419842240

19202176

18562112

17922048

17281984

standardTDAC

standardTDAC

valuedwindow

standardTDAC

Region 2Region 3Region 4no timealiases

Region 1

standardwindows

(a)

0 64 128 192 256 320

1

0

Gain

standardTDAC

standardTDAC

plus zero valuedwindow

standardTDAC

Region 4Region 3Region 2no timealiases

Time (samples)

Region 1

NMM

standardwindowsspecial

window


this coder algorithm uses windows that are combinationsof KBD window segments to tailor the frequency selectiv-ity of all the transform lengths employed. The equationsfor the elementary KBD window shapes are given by

, , ,,

,,

αα

αWW n v N

W k

s k n k

n N0

KBD

k

v

k

N

0

0

1

)

#

!

!^

^

^ ^h

h

h h

8

8

B

B

(3)

with

,

,.

otherwises k

k N v1 0

0

#^ h

R

T

SSS

(4)

Here W is defined by

,

.

,απα

πα

W nI

IN

n N

nN

1 04

4

02

0

0

2

# #

J

L

KK

^

N

P

OO

h

R

T

SSSS

7

V

X

WWWW

A

(5)

with

!.I x

i

x2

i

i0

0

2

3

!

R

T

SSSS

7

V

X

WWWW

A (6)

In Eqs. (3)–(6),n sample numberv overlap in samplesk frequency bin numberi summing index

W Kaiser–Bessel kernel window functionN transform lengthα alpha value for kernel window.

The windows used are combinations of zero-valuedsegments, unity-valued segments, and KBD windows ofthe appropriate lengths. The exact nature of these isexplored when the adaptive transform block structure isdiscussed. The combination of windows, transforms, andthe rewindowing process creates a frame designed for a302- to 446-sample overlap between frames, with a shape

that is the product of encoder and decoder KBD windowswith an α factor of 3.0.

3.3 Design for Splicing Performance Although this arrangement of transforms and windows

works very well when a continuous bit-stream is presentedto the decoder, the quality of a splice, implemented usinga KBD, α factor of 3.0, overlap still sounds inferior com-pared to a simple linear ramp of the same length.Improved splice performance is obtained if the gain as afunction of time is reshaped to be the product of two KBDwindows with α factor of 1.0 rather than 3.0.

This algorithm detects when a splice event occurs andmodifies the rewindowing process to produce the desiredshape. By detecting nonconsecutive frame count values asa bit stream is decoded, the algorithm indicates that asplice has occurred between frames. The rewindowingprocess is the same as that used on start/stop windows [Eq.(2)]. In this equation, each window shape represents theproduct of the encoder and decoder window shapes. Therewindow function is calculated as the desired windowshape divided by the original window shape (in this caseα 3.0).

Fig. 5 shows a 256-sample-length linear ramp com-pared with the shape of the products of two KBD windowswith α factors of 1.0 and 3.0. The KBD product with α 1.0 is a compromise shape between the ramp and a con-ventional KBD product (α 3.0). It provides superiorperformance because it minimizes the discontinuities inslope, while providing only a modest increase in the max-imum rate of change for the gain. This results in signifi-cantly better splice performance over that obtained by ashape defined by the KBD product with α 3.0 and amodest improvement over the performance of the linearramp. Fig. 6 shows that spectral splatter caused by boththe linear ramp and the splice KBD window with α 1.0.

In practice the algorithm rewindows the original over-lap shape (α 3.0) to a shorter length (α 1.0) shapeaugmented with the flat regions of zeros and ones. Table 3shows the normal and splice overlap shapes for each framerate.

4 ADAPTIVE TRANSFORM METHOD

The combination of the requirements for maintaining ahigh coding efficiency for steady-state and transient sig-nals, providing self-editing in the encoded data domain,limiting the encode or decode latency to less than onevideo frame, using power of 2 transform lengths, and sat-isfying the MDCT window-overlap-add constraints,results in the encoder and decoder adaptive transformframe structures shown in Figs. 7 and 8.

In both figures five possible arrangements, or framestates, for a first and second group of transform-windowpairs are shown. These groups are arrangements of thevarious combinations of start, short internal,short–to–long bridge, long–to–short bridge, first long, lastlong, and stop transform–window pairs.

The transform–window types are organized into firstand second groups within a frame to limit coding laten-


Fig. 5. Various frame overlap shapes (product of encoder anddecoder windows).

Linear Ramp

256 samples

KBD alpha = 1

KBD alpha = 3

Time (samples)



10 100 1,000 5,000-140

-120

-100

-80

-60

-40

-20

0

Frame Rate 23.98 Hz

splice frame

linear rampframe

level

Frequency in (Hz)

Fig. 6. Splice frame frequency selectivity compared to linear ramp.

Fig. 7. Encoder window-transform frame structure. (a) 23.98, 24,and 25 Hz. (b) 29.97 and 30 Hz.

Fig. 8. Decoder window-transform frame structure. (a) 24 Hz,nonsplice. (b) 29.97 Hz, nonsplice.

(b)

bridgebridge

0 256 512 768 1024 1280 1536 1792 2048

long long

long

short

bridge

bridgelong

short

Level

Time (samples)

(a)

bridgebridge

0 256 512 768 1024 1280 1536 1792 2048

long long

long

short

bridge

bridgelong

short

Level

Time (samples)2304

(b)

0 256 512 768 1024 1280 1536 1792 2048

longlong

long

short

bridge

bridgelong

short

Level

Time (samples)

bridgebridge

(a)

bridgebridge

0 256 512 768 1024 1280 1536 1792 2048

long long

long

short

bridge

bridgelong

short

Level

Time (samples)2304

Table 3. Normal and splice overlap shapes versus frame rate.

Frame Normal SpliceRate Overlap Overlap(Hz) (samples) (samples)

23.98 302 (α 3.0) 39 zeros, 224, (α 1.0), 39 ones24 304 (α 3.0) 40 zeros, 224, (α 1.0), 40 ones25 384 (α 3.0) 80 zeros, 224, (α 1.0), 80 ones29.97 445 (α 3.0) 111 zeros, 223, (α 1.0), 111 ones30 446 (α 3.0) 112 zeros, 224, (α 1.0), 112 ones


cies, with the second group being a mirror image of thefirst group, reflected at the frame center. The two groupsare classified short, bridge, or long, depending on thearrangement of the transform-window pairs.

The frame states of the encoder and the decoder arematched and synchronized, that is, for example, anencoder “short–short” frame is always associated with adecoder “short–short” frame. Table 4 shows the lengths ofeach window type.

To simplify the implementation, the frame boundaryedges of the encoder windows are either a 256-samplerise/fall (long window) or a 64-sample rise/fall (start/stopwindow), irrespective of the frame rate. For each framerate, the decoder windows are designed to compensate forthis level increase [again using the rewindow function inEq. (2)] so that the combined encoder/decoder windowproduct has the desired overlap length (given in Table 5).

Fig. 8 gives examples of the frame structures for 24 and

29.97 Hz. The 23.98- and 25-Hz frame structures have thesame number of short windows as 24 Hz. The 30-Hz framestructure has the same number of short windows as 29.97 Hz.

The frame transform length of 2048 or 2304 samplesgives rise to a sample overlap between frames that isframe-rate dependent. The use of this overlap interval andthe elimination of time-domain aliases, combined with theneed to code 2048 or 2304 transform coefficients results inthe overhead shown in Table 5. The special 29.97-Hzframe rate will be discussed in more detail in Section 5.

The encoder selects the transform state depending onthe locations of the transients and sends the state informa-tion via the bit stream. Table 6 indicates the relationshipbetween transient event locations and the appropriategroup type states.

The selection of transform block configurations in thismanner prevents audible prenoise and postnoise in thelong–long transform combination, and maximizes the cod-ing efficiency for steady-state signals. The effectiveness ofthe filter-bank formed from the long transform-windowcombination can be compared to that of AC-3 (Fielder etal. [6]). AC-3 is chosen as a reference for coding effi-ciency because of its widespread use, excellent soundquality, and similarly in structure to this system. Fig. 9compares the frequency selectivity characteristics of thelong window of this algorithm to that of the 512-sample


Fig. 9. Steady-state frequency selectivity comparison.

10 100 1000 10000-100

-80

-60

-40

-20

0

long

AC-3

Level (dB)

Frequency (Hz)

Table 6. Sample location of transient versus frame configuration.

First Second Transient LocationSegment Segment (23.98, 24, and 25 HzGroup Type Group Type 29.97 and 30 Hz)

Short Short 960–471832–1343

Long Bridge 1472–23031344–2047

Bridge Long 0–9590–831

Long Long NoneNone

Bridge Bridge 0-959 and 1472–23030–831 and 1344–2047

Table 4. Encoder and decoder transform lengths.

Window-Transform Type Transform Length

Start 256Short 256Short–long bridge 512Long–short bridge 512First long 2048 or 2304Last long 2048 or 2304Stop 256

Table 5. Frame rate versus frame overlap and transform coefficient overhead.

Frame Frame TransformRate Overlap Overhead(Hz) (samples) (%)

23.98 302 15.124 304 15.225 384 20.029.97 446/447 28.0/28.030 448 28.0


transform-window pair used by AC-3.Fig. 9 shows that the frequency selectivity of the long

transform- window combination is significantly betterthan that of AC-3 for frequency separations of less than450 Hz. This is important because the more effectively theencoder is able to isolate tonal components, the more effi-cient the coding system becomes for the representation ofdifficult to code steady- state signals. Also, listeners areespecially sensitive to the presence of coding errors whenpresented with signals containing a large number of har-monics, implying the need for a high bit rate. Fortunatelyif each harmonic is isolated, then little bit rate is needed tocode the frequency regions between them, thus reducingthe number of bits.

This algorithm’s long transform-window pair providesimproved isolation compared to that of AC-3 since it pro-vides more than 12 dB of additional rejection for frequen-cies between 40 and 450 Hz. It also provides more than 15dB of rejection of the frequency gaps between harmonicsspaced 100 Hz or more apart, where as the AC-3 filter bankrequires approximately 2.5 times the frequency separationfor effective isolation. These differences make this systemmore efficient. This is paralleled by a similar improvementin decoder frequency selectivity. Above 450 Hz, the longtransform-window pair has slightly less attenuation thanAC-3; however, its absolute level (less than 65 dB) is lowenough not to impact the coding efficiency.

The combination of a new adaptive transform framestructure, efficient quantization method, large sampletransform length, and a perceptual model similar to thatused by AC-3 results in an audio coding system with acoding efficiency very similar to AC-3 even though theself-editing feature carries a 15 to 28% data-rate penalty.

In conjunction with the new adaptive transform method(and the removal of sample-rate converters), the psychoa-coustic model has been adjusted to give higher soundquality than Dolby E at the expense of reduced tandemcoding generations. Where Dolby E was designed tomaintain excellent quality at up to ten generations, thiscoder has been designed to provide even higher quality atup to three generations. For Dolby E, the transient detec-tion process was designed to be sensitive enough such thatthe coder would properly use short transforms for tran-sient material (in order to minimize pre-noise artifacts) upto the maximum 10 coding generations. The new coder,with its reduced generation constraint, has been adjustedto make more frequent use of long transforms, thusimproving overall coding efficiency. This improved effi-ciency has allowed for adjustments to the hearing thresh-old model so that more bits are allocated to high frequencybands. In tests conducted by Grant et al. [11], eight gener-ations of Dolby E scored 4.87 0.08 (ITU-R five-gradeimpairment scale, and using ANOVA analysis). Informalsubjective and objective tests have shown that the newcoder outperforms Dolby E under these conditions.

5 NTSC, 29.97-Hz FRAME RATE

The frame rate of 29.97 requires special treatment forboth the packed PCM (see Section 6) and ultra-high-quality

audio encoding because the video frame period is a non-integer number of 48 kHz audio samples in length. AsTable 2 shows, the number of samples between frames is1601.6. Because it is necessary to have an integer numberof frame and audio samples for high- quality video andaudio splices, audio samples are organized into groupsassociated with five video frames. This synchronouslyrepeats every 8008 audio samples.

The ultra-high-quality audio coding system and the videoframe synchronous PCM packing provides for self-splicingcapability through the use of crossfading between framesduring splice events. This is done by creating alias-freeframes, appropriate window shapes, and redundant sam-ples, as discussed in Sections 3 and 4. The number sam-ples per frame is the sum of the amount needed if nocrossfade was required, plus the number of redundantsamples to support the crossfade process.

For simplicity, this discussion will set the number ofcrossfade samples to zero. The resultant sample lengthsbecome the sample offsets between all frames and thenonredundant sample lengths for self-editing frames. Inthis scenario, the five-frame grouping of audio samplesshown in Table 7.

This table shows that either 1602 or 1601 audio samplesare associated with each video frame, and the first audiosample at the beginning of each video frame has fractionaltime offsets of 0, 0.2, and 0.4 audio samples relativeto the beginning of the video frame. In nonsplice condi-tions these offsets simply mean that the associated audiowith each frame plays out slightly sooner or later than thebeginning of the video frame, but continuously frame byframe. Splice conditions should only create small frac-tional-sample offsets between spliced audio programs(that is splicing should not create other errors). Note thatthe pattern shown in Table 7 is not a simple alternation of1601 and 1602 blocks because the beginning and end ofthe five-frame blocks have a repeated 1602–1602 pattern.

If audio–video systems provided a means of aligningwith this five-frame pattern and there were no need for anediting resolution less than 167 ms, it would be a simplematter to group the audio samples into blocks of 8008samples associated with five video frames. Unfortunatelymost audio–video systems only provide for audio sampleand video frame synchronization. As a result a decodingsystem may receive audio samples or their equivalents inany one of five possible master-frame alignments. Theseare shown in Table 8.

Table 8 shows the five possible audio frame alignmentswith respect to each other. The double 1602 sequences arein bold for clarity. The irregularity caused by the periodic1602 sample repeat means that some method of translatingone alignment to another must be found which does not


Table 7. Grouping and alignment of audio samplesper five-video-frame block (29.97-Hz frame rate).

Frame Number 1 2 3 4 5

Length (samples) 1602 1601 1602 1601 1602Offset (samples) 0 0.4 0.2 0.2 0.4


produce gaps of audible time errors in the audio signal. The translation method for conversion between the five

alignments is based in the observation that the worst-casetime-alignment error shown in Table 6 is less that 1/2sample and the maximum frame length is 1602 samples.This means that an encoder that includes one or two dupli-cate samples, for a total of 1603 samples, is capable oftranslating continuously one alignment to another withoutloss of information.

The translation between all five possible alignments isperformed by the following technique:

• The encoder assumes one of five audio-sample synchro-nizations relative to video and advances the audio align-ment by the appropriate 1602–1601–1602–1601–1602pattern.

• Frames are labeled 0–1–2–3–4 for the 1602–1601–1602–1601–1602 pattern. The numbers 0–4 aredefined as the encoder frame numbers (Eframe#). Thisinformation is sent to the decoder as metadata.

• All the encoded frames include 1603 samples, wherefirst audio sample begins before the start of the videoframe boundary.

• The decoder assumes its own audio–video frame syn-chronization, and then selects the appropriate samplesfrom each encoded frame to convert the frame to theappropriate 1602–1601–1602–1601–1602 pattern.Expected frames are labeled 0–1–2–3–4 and denotedby decoder frame numbers (Dframe#). The action ofthis scheme is to force the decoder time alignment whena splice occurs but preserves relative time and samplealignment within a spliced sequence.

• The decoder calculates the number of frames it lags fromthe encoder for each incoming frame by the equation

DL [Eframe# Dframe#]modulo 5. (7)

Samples are selected from each encoded frame depend-ing on how much the decoder five-frame alignment lagsthat of the incoming audio. This is done by the rulesshown in Table 9.

Table 9 shows how the samples are selected from theencoder grouping to result in spliced audio data withoutgaps or loss data when conversion from one five-framealignment is made to another.

A graphical example of this translation process is givenin Fig. 10 for the four nonzero frame alignment offsets.This figure shows an example with an encoded framingpattern of 1602–1601–1602–1602–1602 samples. The

shaded samples indicate the redundant samples that areonly needed to support the frame translation process. Notethat all encode frames include a single preframe sampleand sometimes an extra postsample, maintaining a total of1603 samples for all frames. The decoded frames areshown in the bottom part of the figure in time alignmentwith the encoded frames. Examination of Fig. 10 showsthat the selection of the appropriate samples as defined byTable 9 always results in continuously decoded frameswithout gaps or sample losses.

In the audio coding algorithm previously describedthere is an overlap between frames. Fig. 7 shows theencoder window structure. For the 29.97-Hz frame rate,this structure can be considered as 1603 samples (accord-ing to Fig. 10) followed by 445 samples of overlap withthe next frame, the sum being the transform length of 2048samples.

The decoder selects one of the four sample alignmentsor types, and applies the appropriate decoder windowshape. Since the encoder makes no assumption on thedecoder window position when applying its windowshape, the decoder may be required to apply window mod-ification (rewindowing). This ensures that the product ofthe encoder window and the decoder window generatesthe same result as if the encoder window were positioned


Table 8. All possible alignments of audio samplesper five-video-frame block.

Pattern Size Size Size Size Size

1 1602 1601 1602 1601 16022 1601 1602 1601 1602 16023 1602 1601 1602 1602 16014 1601 1602 1602 1601 16025 1602 1602 1601 1602 1601

Table 9. Decoder frame types for conversion between framealignments (29.97-Hz frame rate).

DL Eframe# Type Samples

Encoder and decoder are aligned in time0 0 2 1–16020 1 1 1–16010 2 2 1–16020 3 1 1–16010 4 2 1–1602

Decoder lags the encoder by one video frame1 0 2 1–16021 1 2 1–16021 2 3 2–16021 3 2 1–16021 4 3 2–1602

Decoder lags the encoder by two video frames2 0 1 1–16012 1 0 0–16012 2 2 1–16022 3 1 1–16012 4 2 1–1602

Decoder lags the encoder by three video frames3 0 2 1–16023 1 1 1–16013 2 2 1–16023 3 2 1–16023 4 3 2–1602

Decoder lags the encoder by four video frames4 0 1 1–16014 1 0 0–16014 2 1 1–16014 3 0 0–16014 4 2 1–1602


at the same place as the decoder window. Note that in sit-uations where the beginning or the ending windowrequires modification, the window of its nearest neighborin the frame may also need modification.

Fig. 11 shows the four decoder window translations,which are described as follows:

• Type 0: Samples 0–1601. This frame is 1602 sampleslong. The beginning window is a conventional one inthat the product of it and the encoder window satisfiesthe overlap-add condition. The ending window endsone sample before the end of the encoder window and

is rewindowed. • Type 1: Samples 1–1601. This frame is 1601 samples

long. The beginning window starts one sample after thestart of the encoder window and is rewindowed. Theending window ends one sample before the end of theencoder window and is rewindowed.

• Type 2: Samples 1–1602. This frame is 1602 sampleslong. The beginning window starts one sample after thestart of the encoder window and is rewindowed. Theending window is a conventional one.

• Type 3: Samples 2–1602. This frame is 1601 sampleslong. The beginning window starts two samples after


Fig. 11. Decoder transform-window frame types (29.97-Hz frame rate).

445 1157 445

1602Samples Out

Type 0

445 1156 445

1601Samples Out

Type 1

445 1157 445

1602Samples Out

Type 2

445 1156 445

1601Samples Out

Type 3

Start of Encoder Window

1

2

1

1 1

2

Fig. 10. Frame translation for various decoder frame delays (29.97-Hz frame rate).

16011 1

16011 1

16011 1

16011 1

16011 1

16011602 1602 16021601

Example Encode Frame Block

Decode Framing Translation

1601 1602 1601 1602 1602

160216021602

1602 1602 16021601 1601

1601 1601

16011602 1602 160216012 frames

1 frame

3 frames

4 frames

framealignment


the start of the encoder window and is rewindowed. Theending window is a conventional one.

6 PCM PACKING

In many audio–video distribution applications it may bedesirable to have a means to encapsulate raw PCM sam-ples in synchrony with video. This section brieflydescribes a method for packing PCM at the common videoframe rates of 23.98, 24, 25, 29.97, and 30 Hz. This PCMcoder also provides for editing or splicing at arbitraryframe boundaries and maintains time alignment withinformation encapsulated and coded using the new per-ceptual codec described in previous sections.

6.1 Frame StructureEach PCM frame consists of a block of new samples as

well as 224 additional samples that overlap with the nextframe. Fig. 12 shows the encoder frame structures for allframe rates. As described in the previous section, for the29.97-Hz frame rate, the encoder packs additional samplesthat overlap with both the previous and the next frames tocreate a frame of 1603 samples. In addition to the PCMsamples, other information is also packed into the frame,including the frame count, the fixed point bit depth, and,in the case of the 29.97-Hz frame rate, the encoder framenumber (Eframe# from Table 9).

6.2 designed for Splicing PerformanceAs with the perceptual coder, the PCM coder detects

when a splice event occurs and crossfades the previousframe overlap region with the start of the current frame.This minimizes the possibility of audible artifacts (such aspops, clicks, and thumps) when noncontinuous audio isspliced together.

The decoder uses nonconsecutive frame count values(unpacked from the bit stream) as an indication that a splicehas occurred between frames. The crossfade window is thesame 224-sample KBD (α 1.0) window used in the per-ceptual coder’s splice rewindowing process. Fig. 13 shows anexample of the decoder crossfade for the 24-Hz frame rate.

The use of the overlap samples comes at the cost ofincreased bit-rate and storage requirements. Table 10 givesthe bit-rate increase over linear PCM for a single channel.This can be considered a peak increase since lossless com-pression could be applied to each frame.

7 CONCLUSION

The new audio coding system presented in this engi-neering report has been developed for the distribution ofsound in multichannel audio–video applications. It is avery high-quality transform coding system that uses adap-tive MDCT transforms and a perceptually based bit-allo-


Fig. 13. Decoder splice crossfade and output samples (24-Hz frame rate).

224

Samples Out

PackedSamples

2000

Frame 10

Frame 32

2000

FrameBoundary

FrameBoundary

FrameBoundary

KBD (alpha = 1.0)

Fig. 12. PCM coder frame structure.

23.98 Hz

FrameBoundary

2002 224

2002 224

Frame 1 Frame 2

24 Hz

2000 224

2000 224

25 Hz

224

1920 224

1920

29.97 Hz

224

1602 224

1601

1

1 1

Frame 3

1602 2241

1920

30 Hz

224

1600 224 224

1600

1600

FrameBoundary

FrameBoundary

FrameBoundary

THE AUTHORS


cation process. The requirement to be compatible withvideo editing and switching processes, plus the need tomaintain excellent sound quality despite up to threeencode/decode generations, induced the development of anumber of novel features.

This coder has been optimized for editing and switchingbased on video framing by the incorporation of a framestructure locked to video framing intervals and self-editingcapabilities in the encoded domain. The editing capabilitieshave been achieved through the use of special window-transform combinations at the frame boundaries and theability to tailor frame-to-frame gain profiles during spliceevents. This results in artifact-free splices that are superiorto linear ramp implementations of 256 samples.

The adaptive transform enables the coding of commonvideo frame rates without the use of sample-rate convert-ers. This includes a novel approach to coding noninteger-length frames of audio that occur at the 29.97-Hz framerate, while still enabling arbitrary frame splicing.

The new PCM packing method presented has also beendeveloped for multichannel audio–visual applications,more specifically where lossless distribution of audio isrequired. This PCM coder also provides for frame-basedediting and artifact-free splicing with a modest increase inbit-rate and storage requirements.

8 REFERENCES

[1] L. D. Fielder and C. C. Todd, “The Design of aVideo Friendly Audio Coding System for DistributionApplications,” presented at the AES 17th InternationalConference (1999 Sept.), paper 17-008.

[2] AES-3id-1995, “AES Information Document forDigital Audio Engineering—Transmission of AES3Formatted Data by Unbalanced Coaxial Cable,” AudioEngineering Society, New York (1995).

[3] J. P. Princen and A. B. Bradley, “Analysis/SynthesisFilter Bank Design Based on Time-Domain AliasingCancellation,” IEEE Trans. Acoust. Speech, SignalProcess., vol. ASSP-34, pp. 1153–1161 (1986 Oct.).

[4] H. S. Malvar, Signal Processing with Lapped Trans-forms (Artech House, Boston, MA, 1992), pp. 143–173.

[5] C. J. Moore and B. R. Glasberg, “FormulaeDescribing Frequency Selectivity as a Function of Frequencyand Level, and Their Use in Calculating Excitation Patterns,”Hear. Res., vol. 28, pp. 209–225 (1987).

[6] L. D. Fielder, M. A. Bosi, G. A. Davidson, M. F.Davis, C. Todd, and S. Vernon, “AC-2 and AC-3: Low-Complexity Transform-Based Audio Coding,” inCollected Papers on Digital Audio Bit-Rate Reduction, N.Gilchrist and C. Grewin, Eds. (Audio EngineeringSociety, New York, 1996), pp. 54–72.

[7] M. Truman, G. Davidson, A. Ubale, and L. D.Fielder, “Efficient Bit Allocation, Quantization, andCoding in an Audio Distribution System,” presented at the107th Convention of the Audio Engineering Society, J.Audio Eng. Soc. (Abstracts), vol. 47, pp. 1003–1004(1999 Nov.), preprint 5068.

[8] K. Brandenburg, G. Stoll, Y. F. Dehery, J. D.Johnston, L. Van Der Kerhof, and E. F. Schroder, “ISO-MPEG-1 Audio: A Generic Standard for Coding of High-Quality Digital Audio,” in Collected Papers on DigitalAudio Bit-Rate Reduction, N. Gilchrist and C. Grewin, Eds.(Audio Engineering Society, New York, 1996), pp. 31–42.

[9] M. Bosi, K. Brandenburg, S. Quackenbush, L. D.Fielder, K. Akagiri, H. Fuchs, M. Dietz, J. Herre, G. Davidson,and Y. Oikawa, “ISO/IEC MPEG-2 Advanced Audio Coding,”J. Audio Eng. Soc., vol. 45, pp. 789–814 (1997 Oct.).

[10] F. J. Harris, “On the Use of Windows forHarmonic Analysis of the Discrete Fourier Transform,”Proc. IEEE, vol. 66, pp. 51–83 (1975 Jan.).

[11] D. B. Grant, G. A. Davidson, and L. D. Fielder,“Subjective Evaluation of an Audio Distribution CodingSystem,” presented at the 111th Convention of the AudioEngineering Society, J. Audio Eng. Soc. (Abstracts), vol.49, p. 1222 (2001 Dec.), paper 5443.


Table 10. PCM coder peak bit-rateincrease over linear PCM

Frame Bit-RateRate Increase(Hz) (%)

23.98 11.224 11.225 11.729.97 14.030 14.0

M. J. Smithers B. G. Crockett



Michael J. Smithers was born in Penrith, Australia, in1973. He received a Bachelor in Engineering - Electrical(Honours, First Class) degree, with a major in signalprocessing from the University of Wollongong,Australia, in 1997. From 1997 to 2000 he worked atMotorola Labs in Sydney, Australia, as a researcher insuch areas as very low bit-rate speech coding and speechrecognition. In 2000 he joined Dolby Laboratories inSan Francisco, California, where he has worked in audiocompression for music, broadcast and cinema, as well asmusic identification and loudness measurement.

Brett G. Crockett received an MSEE degree from theUniversity of Illinois in Champaign/Urbana, Illinois and aBSEE degree from the University of Iowa, Iowa City, Iowa.

Mr. Crockett spent eight years at TRW-ESL and

Applied Signal Technology, both of Sunnyvale,California, working on signal processing solutions fortelecommunication systems. In 1997 he joined DolbyLaboratories as a member of the Research Department.He was leader of the core-algorithm research and devel-opment team for the Dolby E encoder and decoder prod-ucts. He has also played a key role in the research anddevelopment of the Dolby Digital professional encoderalgorithm and product line. Currently Mr. Crockett isworking in the fields of audio coding, audio identificationand watermarking, loudness measurement and control,auditory scene analysis, and high-quality time-scaling andpitch-shifting algorithms.

The biography of Louis D. Fielder was published in the2003 January/February issue of the Journal.

ENGINEERING REPORTS

0 INTRODUCTION

Currently vacuum tubes are enjoying a renaissanceespecially in the area of high-fidelity audio amplifiers (seeexample [1]–[6]). This is attributed to the difference in thesound produced by vacuum-tube and solid-state ampli-fiers. Over the years it has been argued that a givenamount of third-order distortion sounds worse than thesame percentage of second-order distortion. Based on thisargument, it has been postulated that the principle reasonfor the difference in sound, between vacuum-tube andsolid-state amplifiers, is their harmonic distortion per-formance [7]. This argument was recently supported bySPICE simulation results [8], which show that the secondharmonic distortion of a vacuum triode amplifier is almostequal to its total harmonic distortion (THD). Usually, inSPICE the THD of an amplifier is calculated by applyinga sinusoidal signal to the input and analyzing the outputwaveform using Fourier analysis. While the calculatedTHD may serve as a measure of the nonlinear perform-ance of an amplifier, audio amplifiers are expected to han-dle more complicated multisinusoidal signals. The inter-modulation distortion (IMD), therefore, presents ameasure that is closer to the practical audio amplifieroperation regime than the THD. In fact it is argued thatTHD figures are irrelevant, irrational, and completely spu-rious and that IMD is far more relevant. Unlike THD, IMDreflects how an amplifier sounds [9]. Moreover, it is

argued that while IMD does degrade the amplifier per-formance, second-or third-harmonic distortion is not onlynot unpleasant but is sometimes positively preferred bythose who like valve sound [9].

Again, IMD performance can be calculated usingSPICE by performing transient analysis of the amplifierwith a multisinusoidal input signal followed by a Fourierdecomposition of the output signal. Obviously the accu-racy of the results obtained relies on the accuracy of theequations used to model the active devices used in theamplifier design. Recently, and owing to the resurgence ofthe vacuum tubes, a number of accurate models have beendeveloped for the triode and the pentode [8], [10]–[16].However, the major drawback of this technique is that it isnot computationally simple as it has to be repeated for dif-ferent input scenarios. Moreover, SPICE cannot be a sub-stitute for the thought-process provided by a hand analy-sis using simple models for the active devices. A betterinsight into the operation of electronic circuits and a sys-tematic way of getting a preliminary understanding of thecircuit performance can be gained by hand analysis usingsimple device models. Then circuit simulation by meansof SPICE can be used to obtain more accurate results andto verify the results obtained by hand calculations.Furthermore, circuit simulation may suffer a wide range ofproblems, particularly those arising from the discretenature of the solution methods used to analyze problemsof a continuously nonlinear nature [17].

It is therefore, the major intention of this engineeringreport to present a simple technique for calculating the


Large-Signal Analysis of TriodeVacuum-Tube Amplifiers*

MUHAMMAD TAHER ABUELMA’ATTI

King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia

A mathematical model for the input–output characteristic of a single-stage triode vacuum-tube amplifier is presented. The model, basically a cosine-series function, can easily yieldclosed-form series expressions for the amplitudes of the output components resulting frommultisinusoidal input signals to the amplifier. The special case of an equal-amplitude two-tone input signal is considered in detail. The results show that, similar to transistor-basedamplifiers, the vacuum triode amplifier generates both even- and odd- order harmonic andintermodulation components. The results also show that the amplitudes of these componentsare strongly dependent on the tube parameters, the biasing voltage, and the amplitudes of theinput tones and are not following a general pattern.

Manuscript received 2002 January 30, revised 2003 August 4.

ENGINEERING REPORTS ANALYSIS OF TRIODE VACUUM-TUBE AMPLIFIERS

harmonic and intermodulation performance of vacuum tri-ode amplifiers.

The proposed technique enjoys the following attractivefeatures:

1) It can be implemented without recourse to extensivecomputing facilities and well-developed software.

2) It can yield closed-form expressions for the ampli-tudes of the harmonic and intermodulation productsresulting from a multisinusoidal input.

1 ANALYSIS

A simplified vacuum triode amplifier is shown in Fig. 1.With positive plate-to-cathode voltage and negative grid-to-cathode voltage, the grid current of the vacuum triodecan be ignored and the total instantaneous plate currentcan be approximately expressed as [18]

,

, <

, <

µ

µ

µ

K

for

for

i v v

v v v

i v v

0 0

0 0

p GK PK

GK PK PK

p GK PK

3 2

$

_ i

(1a)

(1b)

where K and µ are constants determined by the particulartube, and iP, vGK, and vPK are the anode-current, grid-to-cathode, and anode-to-cathode voltages, respectively. Eq.(1a) is valid only when vGK is negative. In fact Eq. (1a)describes the total cathode current. Thus when vGK is pos-itive, a grid current will flow and the plate current cannotbe described by Eq. (1a).Using Eq. (1), the input-voltage/output-voltage character-istic of the amplifier of Fig. 1 can be expressed as (seeAppendix)

,

,

<

, <

γ µ λ

µ λ

µλ

µ λ

for

for

x y y

x y

x y

y x y

1 1 1 1 1

1 1 1 1 0

1 0

1 1 1 1 1 0

2 3

$

_ _ _

_ _

_

_ _

i i i

i i

i

i i

8

8

8

B

B

B

(2a)

(2b)

where

Vγ

λ

KR

R

R

1

p pp

p

k

2 3 1 3a k

and

µx

V

v

pp

in

a k

is the normalized input voltage,

yV

v

pp

o

a k

is the normalized output voltage, Rp is the anode resist-ance, Rk is the cathode resistance, and Vpp is the dc supplyvoltage of the amplifier of Fig. 1. Eq. (2) is nonlinear andcan therefore be used to calculate the harmonic and inter-modulation performance of the vacuum triode amplifier ofFig. 1 when excited by a multisinusoidal input signal.However, in its present form Eq. (2) represents the inputvariable as a function of the output variable, whereas whatis required is an expression for the output variable as afunction of the input variable. Alternatively, over the yearsthe plate current was described by a Taylor series expan-sion in terms of the gate-to-cathode voltage and the five-point method was used to calculate graphically the ampli-tudes of the output harmonics resulting from exciting thetube by a single sinusoid [18], [20]–[22]. For obvious rea-sons this approach cannot be extended to the calculationof the amplitudes of output intermodulation productsresulting from exciting the tube by a multisinusoidal sig-nal. Using a slightly different approach, the transfer char-acteristic of the tube can be approximated by a slidingpower law function [23]. While this approach can yieldaccurate estimates of the amplitudes of the intermodula-tion products, its implementation requires extensivenumerical Fourier analysis and cannot yield closed-formexpressions.

Here we propose to represent Eq. (2) by the Fourierseries model of Eq. (3)

.cosπ

y a aT

nx

2 n

n

N

01

! e o (3)

The parameters T, a0, and an in Eq. (3) can be obtainedusing the procedure described in [24], [25]. This proce-dure is simple and does not require extensive computingfacilities or well-developed software. For convenience, abrief description of this procedure is given here. First, fora given value of the parameters λ and γ, the input-outputcharacteristic of Eq. (2) is mirror imaged to obtain a com-plete period T. Second, the resulting characteristic isapproximated by a number of straight-line segmentsjoined end to end. Using the slopes of these segments, it iseasy to obtain the parameters T, a0, and an using simplealgebraic calculations [24], [25]. Samples of the results


Fig. 1. Simple vacuum triode amplifier.

inv

ov

ppV

pR

kR

ABUELMA’ATTI ENGINEERING REPORTS

obtained are shown in Table 1 for different values of λ.Using Eq. (3) and the parameters of Table 1, the input-out-put characteristic of the vacuum triode amplifier of Fig. 1was calculated and compared with Eq. (2). The resultsshow that very small values of the relative root-mean-square (rrms) errors can be achieved. This confirms thevalidity of Eq. (3) for approximating the input-outputcharacteristic of Eq. (2).

2 HARMONIC AND INTERMODULATIONPRODUCTS

Eq. (3) can be used for predicting the amplitudes of theharmonics and intermodulation products of the normal-ized output voltage y when the normalized input x isformed of a multisinusoidal signal of the form

,sinωx X X t X X1 0 mm

M

m mm

M

01

01

# #! !

(4)

where X0 is a negative quantity that represents the normal-ized bias voltage of the input. Combining Eqs. (3) and (4)and using the trigonometric identities

sin sin sin

cos sin cos

β ω β ω

β ω β β ω

t J l t

t J J l t

2 2 1

2 2

ll

ll

2 10

0 21

3

3

!

!

_ _ ^

_ _ _ ^

i i h

i i i h

where Jl (β) is the Bessel function of order l, and aftersimple mathematical manipulations, it is easy to showthat the amplitude of the normalized output voltage com-ponent of frequency α ωmm m1

M! and order αmm 1M! ,

where αm is a positive or negative integer or zero, will begiven by

,

,

sin

cos

π

πα

π

πα

for odd

for even

Y aT

nX

JT

nX

Y aT

nX

JT

nX

22

2

22

2

, , ,

, , ,

α α α

α

α α α

α

nn

N

m

M

m mm

M

nn

N

m

M

m mm

M

01

1 1

01

1 1

M

m

M

m

1 2

1 2

f

f

!

% !

!

% !

_ e

e

_ e

e

i o

o

i o

o

R

T

SSS

R

T

SSS

V

X

WWW

V

X

WWW

(5a)

(5b)

Using Eqs. (5), the amplitude of the normalized outputvoltage component of frequency ωr, r 1, 2, … , M, willbe given by

J

m ! r

sinπ π π

Y aT

nX

T

nX J

T

nX2

2 2 2 n

n

N

rm

M

m1 01

1 01

! %e e eo o o

R

T

SSS

V

X

WWW

(6)

The amplitude of the kth harmonic component of fre-quency kωr of a normalized output voltage will be given


Table 1. Values T, a0, and an for triode amplifier of Fig. 1 with Vpp 180 V,Rp 220 kΩ, µ 83.5, K 1.73 10– 06.

λ 0.0 0.0005 0.001 0.002T 4.000 4.213 4.39988 4.75840a0 0.828037 0.842130 0.853188 0.868990a1 0.283127 0.265116 0.250000 0.223100a2 0.150698 0.151157 0.149536 0.144310a3 0.042334 0.050061 0.055289 0.063418a4 0.004658 0.006520 0.008872 0.014807a5 0.010632 0.007101 0.004895 0.002748a6 0.015484 0.014318 0.012505 0.008264a7 0.007842 0.010369 0.011575 0.011689a8 0.001640 0.002911 0.004538 0.007700a9 0.003269 0.001687 0.001203 0.002341a10 0.005326 0.004347 0.003056 0.001155a11 0.003166 0.004403 0.004550 0.003061a12 0.000877 0.001833 0.002926 0.003944a13 0.001586 0.000741 0.000883 0.002485a14 0.002624 0.001837 0.000999 0.000797a15 0.001682 0.002361 0.002090 0.000751a16 0.000556 0.001301 0.001962 0.001674a17 0.000947 0.000474 0.000855 0.001874a18 0.001546 0.000916 0.000451 0.001064a19 0.001036 0.001412 0.001007 0.000388a20 0.000392 0.000972 0.001301 0.000581a21 0.000635 0.000377 0.000799 0.001080a22 0.001002 0.000518 0.000325 0.001046a23 0.000683 0.000903 0.000508 0.000542a24 0.000286 0.000742 0.000846 0.000268a25 0.000462 0.000318 0.000699 0.000486rrms error (%) 1.43 0.74 0.30 0.03


for k odd by

J

m ! r

sinπ π π

Y aT

nX

T

nX J

T

nX2

2 2 2k n

n

N

k rm

M

m01

01

! %e e eo o o

R

T

SSS

V

X

WWW

(7a)

and for k even by

(7b)

The amplitude of an intermodulation product of fre-quency kωr, ± qωs and order k q will be given for k q odd by

J J

, sm r!

sinπ π π

π

Y aT

nX

T

nX

T

nX

JT

nX

22 2 2

2

,k q nn

N

k r q s

m

M

m

01

01

!

%

e e e

e

o o o

o

R

T

SSS

V

X

WWW

(8a)

and for k q even by

J J

, sm r!

cosπ π π

π

Y aT

nX

T

nX

T

nX

JT

nX

22 2 2

2

,k q nn

N

k r q s

m

M

m

01

01

.

!

%

e e e

e

o o o

o

R

T

SSS

V

X

WWW

(8b)

In a similar way the amplitude of an intermodulationproduct of any order can be obtained using Eqs. (5).

3 SPECIAL CASE

To illustrate the use of Eqs. (6)–(8), the special case ofan input signal formed of two equal-amplitude sinusoidsof the form

sin sinω ωx X X t t 0 1 2_ i (9)

will be considered. Using Eq. (6), the amplitude of anoutput product of frequency ω1 (or ω2) will be givenby

J J .sinπ π π

Y aT

nX

T

nX

T

nX2

2 2 2 n

n

N

1 01

1 0

! e e eo o o

R

T

SSS

V

X

WWW

(10)

The amplitude of a second-harmonic component of fre-quency 2ω1 (or 2ω2) will be given by

J J .cosπ π π

Y aT

nX

T

nX

T

nX2

2 2 2 n

n

N

2 01

2 0

! e e eo o o

R

T

SSS

V

X

WWW

(11)

The amplitude of a third-harmonic component of fre-quency 3ω1 (or 3ω2) will be given by

J J .sinπ π π

Y aT

nX

T

nX

T

nX2

2 2 2 n

n

N

3 01

3 0

! e e eo o o

R

T

SSS

V

X

WWW

(12)

The amplitude of a second-order intermodulation compo-nent of frequency (ω1 ± ω2) will be given by

J Jcosπ π π

Y aT

nX

T

nX

T

nX2

2 2 2, n

n

N

1 1 01

1 1

! e e eo o o

R

T

SSS

V

X

WWW

(13)

Finally the amplitude of a third-order intermodulationcomponent of frequency (2ω1 ± ω2) or (2ω2 ± ω1) will begiven by

J Jsinπ π π

Y aT

nX

T

nX

T

nX2

2 2 2, n

n

N

2 1 01

2 1

! e e eo o o

R

T

SSS

V

X

WWW

(14)

Combining Eqs. (10)–(14), the relative harmonic andintermodulation distortion can be expressed as

HDY

Y2

1

2 (15)

HDY

Y3

1

3 (16)

IMDY

Y ,

21

1 1 (17)

.IMDY

Y ,

31

2 1 (18)

Using Eqs. (15)–(18) and Table 1, the harmonic and inter-modulation performance of the vacuum-tube triode ampli-fier of Fig. 1 was calculated and the results are shown inFig. 2. From Fig. 2 it appears that the harmonic and inter-modulation performance of the vacuum triode amplifier ofFig. 1 is a function of the parameter λ Rk/Rp , the nor-malized bias voltage X0, and the normalized amplitude ofthe input tones. However, it appears that while the third-order harmonic and intermodulation performance isstrongly dependent on the parameter λ, the second-orderharmonic and intermodulation performance is lessdependent. This implies that whereas the negative feed-back introduced by the resistance Rk, has a large effect onthe odd-order nonlinearities, its effect on the even-ordernonlinearities is much less. In fact it is well known thatnegative feedback is not a cure to all orders of nonlineari-ties [26]. Thus in the present case, while it reduces thethird-order nonlinearity, its overall effect on the second-order nonlinearity is negligible. From Fig. 2 it appears


J

m ! r

cosπ π π

Y aT

nX

T

nX J

T

nX2

2 2 2k n

n

N

k rm

M

m01

01

! %e e eo o o

R

T

SSS

V

X

WWW

.


also that, compared to the harmonic components, theintermodulation components of the same order are domi-nant. Moreover, it appears that the second-order intermod-ulation is the most dominant component. Furthermore, forVpp 180 V, Rp 220 kΩ, K 1.73 10– 06, µ 83.5and λ 0.0 (Rk 0.0 Ω), an input signal amplitude 0.2V (X 0.093) and a dc grid biasing voltage –0.64 V(X0 –0.3) corresponding to a dc anode biasing current

.0 8, mA, the calculated and simulated second-harmonicdistortion are –44 dB and –42 dB, respectively. Theseresults show that calculations made using the presentanalysis are in excellent agreement with the SPICE simu-

lation results reported in [8] and indicate that the principaldistortion generated by the vacuum triode amplifier of Fig.1 is of second order. However, whereas in [8] only the har-monic distortion was calculated, the present analysis pro-vides a further insight and shows that it is the second-order intermodulation component that is dominant.

4 CONCLUSIONS

A simple yet powerful technique has been presented forobtaining a mathematical model for the input-output char-acteristic of the simple vacuum triode amplifier of Fig. 1.


Fig. 2. Harmonic and intermodulation performance of vacuum triode amplifier of Fig. 1. Vpp 180 V, Rp 220 kΩ, K 1.73 10– 06

µ 83.5, X0 –0.3. — IMD2; IMD3; * HD2; HD3.(a) λ 0.0 (Rk 0.0). (b) λ 0.0005 (Rk 110 Ω). (c) λ 0.001 (Rk 220 Ω). (d) λ 0.002 (Rk 440 Ω).

(a)

(b)


The parameters of the model can be easily extracted usingsimple calculations without recourse to Taylor seriesexpansions and series reversion techniques. Using thismodel, closed-form expressions have been obtained forthe amplitudes of the harmonics and intermodulationcomponents resulting from exciting the vacuum triodeamplifier of Fig. 1 by a multininusoidal input signal. Thespecial case of an equal-amplitude two-tone input signalwas considered in detail. The results obtained clearlyshow that similar to the equivalent transistor-based ampli-fier [27], the vacuum triode amplifier of Fig. 1 generatesboth even- and odd-order harmonic and intermodulationcomponents when excited by multisinusoidal signals. The

results also show that the harmonic and intermodulationperformance strongly depend on the biasing, the ampli-tude of the input tones, and the parameter λ Rk/Rp.Moreover, the second-order intermodulation componentis always dominant. In this respect, the harmonic andintermodulation performance of the vacuum triode-basedamplifier of Fig. 1 is similar to that of the equivalent tran-sistor-based amplifiers [28], [29]. However, care is neces-sary if the results of the vacuum triode-based and the tran-sistor-based amplifiers are used to compare theirlarge-signal performances. A direct comparison is validonly for same sinusoidal input amplitudes.

It is therefore reasonable to expect that the results of a


Fig. 2. Continued

(c)

(d)


subjective test may not support the hypothesis on the dif-ference between vacuum tube and transistor-based ampli-fiers [30]. It remains, however, to investigate the harmonicand intermodulation performance of vacuum tube outputstages in comparison with transistor-based ones.

5 REFERENCES

[1] J. Linsley Hood, Valve and Transistor AudioAmplifiers, (Newnes, 1997).

[2] F. Langford-Smith, Radio Designer’s Handbook,(Newnes, 1997).

[3] R. A. Pittman, The Tube Amp Book II, (GrooveTubes, Sylmar, CA, 1988).

[4] J. L. Stewart, “Triode Audio Amplifier withBootstrapping,” Electron. World, vol. 104, p. 570 (1998July).

[5] C. C. Wong, “Valve-Based Time-AlignedLoudspeaker Crossover Filter,” Electron. World, vol 107,p. 789 (2001 Oct.).

[6] W. de Hann, K. Brakenhof, and K. Huevelman,“DC-Coupled Valve Power,” Electron. World, vol. 107, pp.61–63 (2001 Jan.).

[7] I. Hickman, “Zero Distortion?,” Electron. World,vol. 105, pp. 224–228 (1999 Mar.).

[8] W. M. Leach, “SPICE Model for Vacuum-TubeAmplifiers,” J. Audio Eng. Soc., vol. 43, pp. 117–126(1995 Mar.).

[9] A. New, “THD Is Meaningless,” Electron. World,vol. 106, pp. 440–447 (2000 Jun.).

[10] E. K. Pritchard, W. M. Leach, “Comments onSPICE Models for Vacuum-Tube Amplifiers,” J. AudioEng. Soc. (Letters to Editor), vol. 45, pp. 488–489 (1997June).

[11] F. Broyde, E. Clavelier, C. Hymowitz, C. Rydel,and W. M. Leach, “Comments on SPICE Models forVacuum-Tube Amplifiers,” J. Audio Eng. Soc. (Letters toEditor), vol. 45, pp. 490–496 (1997 June).

[12] W. Sjursen, “Improved SPICE Model for TriodeVacuum Tube,” J. Audio Eng. Soc., vol. 45, pp.1082–1088 (1997 Dec.).

[13] “Spice Model for a Vacuum Triode,” IntusoftNewsle. no. 12, pp. 1–6 (1989 Feb.).

[14] “Modeling Vacuum Tubes, Intusoft Newsl. no. 34,pp. 6–11 (1994 Feb.).

[15] “Modeling Vacuum Tubes, Intusoft Newsl. no. 35,pp. 7–11 (1994 Apr.).

[16] S. Reynolds, “Vacuum-Tube Models forPspice Simulations,” Glass Audio, vol. 5, pp. 17 – 23(1993).

[17] P. Mole and H. Rokos, “ Techniques for NonlinearCircuit Simulation,” Editorial, Proc. IEE—Circuit DevicesSystems, vol. 141, p. 241 (1994).

[18] K. R. Spangenberg, Fundamentals of ElectronDevices (McGraw-Hill, New York, 1957), ch. 15.

[19] C. A. A. Wass, “A Table of IntermodulationProducts,” J. EE, vol. 95, p. III. pp. 31–39 (1948).

[20] S. Seely, Electron Tube Circuits (McGraw-Hill,New York, 1958), ch. 2.

[21] J. Millman, Vacuum-Tube and Semiconduc-

tor Electronics (McGraw-Hill, New York, 1958),ch. 16.

[22] J. D. Ryder, Engineering Electronics (McGraw-Hill, New York, 1967), ch. 6.

[23] R. Bachmannn and S. Strassler, “IntermodulationDistortion Analysis of Static Characteristics ofTransmitter Tubes,” Brown Boveri Rev., vol. 9, pp.458–463 (1977).

[24] M. T. Abuelma'atti, “Simple Method forCalculating Fourier Coefficients of ExperimentallyObtained Waveforms,” Proc. IEE—Sci. Measurement,Techno., vol. 141, pp. 177–178 (1994).

[25] M. T. Abuelma'atti, “A Simple Algorithm forFitting Measured Data to Fourier-Series Models,” Int. J.Ma. Educ. Sci. and Technol., vol. 24, pp. 107–112(1993).

[26] M. T. Abuelma‘atti, “Linear Negative Feedbackand Nonlinear Distortion,” Int. J. Appl. Eng. Educ., vol. 6,pp. 103–105 (1990).

[27] M. T. Abuelma'atti, “The Spectrum of CurrentComponents in Semiconductor Junction Diodes andBipolar Junction Transistors,” Int. J. Ele. Eng. Educ., vol.21, pp. 39–45 (1984).

[28] M. T. Abuelma'atti, “Harmonic andIntermodulation Performance of Nonlinear ElectronicCircuits,” Active Passive Electron. Compon., vol. 21, pp.87–105 (1998).

[29] P. Garde, “Slope Distortion and AmplifierDesign,” J. Audio Eng. Soc., vol. 26, pp. 602–608 (1978Sept.).

[30] O. M. Reshetnikov, R. Kh. Khestanov, and Y. V.Chernyk, “Vacuum Tubes and Transistors in AudioAmplifiers,” Telecommun. Radio Eng., vol. 38/39, pp.121–123 (1984 Dec.).

APPENDIX

Using Fig. 1,

v v i R GK in p k (19)

v V i R R PK pp p k pa k (20)

.v V i R o pp p p (21)

Combining Eqs. (19)–(21) and Eq. (1a), then

.

µR

V vK v

R

V v R

VR

V vR R

p

ppin

p

pp k

ppp

ppp k

o o

o

3 2

J

L

KKK

a

a

N

P

OOO

k

k

R

T

SSSS

V

X

WWW

(22)

Using Eq. (22), with γ 1/[(KRp)2/3Vpp

1/3], λ Rk/Rp, x vin/(Vpp/µ), and y v0/Vpp, simple mathematical manipu-lations lead to Eq. (2a) and 2b).




THE AUTHOR

Muhammad Taher Abuelma'atti was born in Cairo, Egypt,in 1942. He received a B.Sc. degree in electrical engineeringfrom the University of Cairo, Cairo, Egypt, in 1963 andPh.D. and Doctor of Science degrees from the University ofBradford, Bradford, UK, in 1979 and 1999, respectively.

In 1963 Dr. Abuelma'atti worked at the MilitaryTechnical College in Cairo as a teaching assistant. He thenjoined the Iron and Steel Company in Helwan, Cairo, assenior electrical engineer in 1967. From 1973 to 1976 hewas a teaching assistant at the College of Engineering,University of Riyadh, Saudi Arabia. In 1980 he worked asan assistant professor in the Faculty of Engineering,University of Khartoum, Sudan. He was an assistant pro-fessor at the College of Engineering, King SaudUniversity, Riyadh, Saudi Arabia from 1981 to 1982. Hejoined the College of Engineering, University of Bahrainin 1982, and in 1987 he became an associate professor.Currently he is a full professor at the College of

Engineering Sciences, King Fahd University of Petroleumand Minerals, Dhahran, Saudi Arabia.

Dr. Abuelma'atti is the recipient of the 1994/1995Excellence in Teaching Award and the 1995/1996 and2000/2001 Excellence in Research Award while workingat King Fahd University of Petroleum and Minerals. He isa contributor to Survey of Instrumentation andMeasurement, S. A. Dyer, editor (John Wiley, 2001); TheEncyclopedia of Electrical and Electronic Engineering, J.G. Webster, editor (John Wiley, 1999); and SelectedPapers on Analog Fiber-Optic Links, E. I. Ackerman,C. H. Cox III, and N. A. Riza, editors (SPIE OpticalEngineering Press, 1998). He is also the author or co-author of over 500 journal articles and technical presenta-tions. Dr. Abuelma'atti’s research interests include prob-lems related to analysis and design of nonlinear electroniccircuits and systems, analog integrated circuits, and activenetworks design.

ENGINEERING REPORTS


0 INTRODUCTION

Little is known about historical theatrical buildings inChina compared to the understanding of room acoustics inwestern concert halls and theaters, although Chinese tra-ditional opera represents the culmination and distillationof 2000 years of civilization. The construction of theatersin China evolved during the Song dynasty (A.D.960–1276) and spread throughout China during the Mingdynasty (A.D. 1363–1644). Most of the historical build-ings being preserved were built in the eighteenth and nine-teenth centuries, but the oldest ones can be traced back tothe thirteenth century [1]. In the past few years researchefforts by Wang covered the historical development ofChinese theaters and their acoustics. The theaters werecategorized into three types, according to their spatialcomposition and historical evolution: the amphitheater,the courtyard, and the auditorium [2], [3].

Chinese traditional opera is a comprehensive performingart that combines singing, music, dialogue, pantomime,and martial arts. The singing voice plays the most impor-tant role and is normally accompanied by a relatively smallinstrumental group. A large variety of forms exist, whichcan be differentiated by the use of local dialects andmelodies. Based on surveys of auditorium-type theaters,Xiang suggested an optimum midfrequency (500- and

1000-Hz octave bands) reverberation of 1.0 s to balancebetween speech intelligibility and music liveness [4].Kyoungsoo and Sung recommended a similar value fortraditional Korean music by a Korean lute and a pipeinstrument [5]. Besides reverberation, Wang stressed theimportance of strength and clarity, especially in the highfrequencies where the formants by well-trained singersallowed the voices to be heard at a remote distance [3].Bass sounds and lateral reflections were generally con-sidered to be less important while very few orientalinstruments emitted sound energy below 130 Hz [3], [6].A good sight line provided by the small size of the the-aters was preferable both acoustically and visually.Symbolic acting required a small-size stage, which pro-vided good acoustical support to the actors and musi-cians. However, problems might have arisen when actorsfaced away across a stage that was surrounded by theaudience on three sides [3]. Overall, the concept of goodacoustics for Chinese theaters was not so different fromwhat is suggested for modern theaters, except for theinfluence of the fly tower.

In the east and south coastal areas of China, courtyard-typetheaters were built in temples and guildhalls [3], [7], [8]. Thestage was attached to a courtyard surrounded by walls orcovered galleries. Most of the existing theaters were pub-lic buildings and shared some common architectural fea-tures. For example, the platform was normally raised toone story high, the stage was set tightly against on one

Acoustical Measurements of Traditional TheatersIntegrated with Chinese Gardens*

WEIHWA CHAING, YENKUN HSU, AND JINJAW TSAI

Department of Architecture, National Taiwan University of Science and Technology, Taipei 106, China (Taiwan)

AND

JIQING WANG AND LINPING XUE

Institute of Acoustics, Tongji University, Shanghai 200092, China

Acoustical measurements were taken in three traditional theaters integrated with Chinesegardens. Each theater consisted of a pavilion-like stage inside a courtyard surrounded bycovered galleries, walls, or rock piles. The courtyard was generally rectangular in shape.Water, rocks, bridges, walls, and vegetation made the theater space rather irregular. Allmeasurements were taken when the floors were unoccupied and without seats. Analysisshowed an average strength G of 4.7 dB, an average early decay time EDT of 0.74 s, and anaverage early support STE of –9.3 dB.

*Manuscript received 2002 December 2; revised 2003 August 25.

ENGINEERING REPORTS ACOUSTICAL MEASUREMENTS OF TRADITIONAL THEATERS


side of the courtyard, and the courtyard was generallysymmetrical in plan. The platform was raised because ofthe standing audiences inside the courtyard. In the unoc-cupied condition, the absence of a roof and the presence ofan audience would mean little reverberant energy. The sit-uation is similar to Elizabethan theaters built in the six-teenth and seventeenth centuries—acoustically and archi-tecturally [9], [10].

Unlike most courtyard-type theaters within publicbuildings, which were strictly rectangular and symmetri-cal, the theater integrated with a privately owned Chinesegarden was standing out as a unique type. From case tocase rather diversified designs were found. The use ofwater, rocks, bridges, walls, and vegetation makes themrather irregular in form [11].

The current study was conducted to understand theacoustical conditions in theatrical venues integrated withhistorical Chinese gardens. All measurements were takenin the unoccupied conditions. Since it is difficult to tracehow exactly the theaters were used in the past, the study israther aimed at contemporary uses.

1 THEATERS STUDIED

The subjects included one theater in mainland China,the Jixiao Manor in He Yuan (JM) Yangzhou, and two inthe Lin Family residence in Taipei, Taiwan, the Pavilionfor Drama (PD) and the Fangchien Studio (FS) [12]–[14].All theaters were built in the nineteenth century. “Kunqu”(popular mainly in Jiangsu) and “Beiguan” (popular inFujian and Taiwan) were the major opera forms for thetwo geographical areas.

Table 1 compares the architectural dimensions of thethree theaters. Instead of being attached directly to thefront perimeter of the theater, all three stages were movedinto the courtyard, at an average distance of 5.5 m fromthe back wall. The small platform area allowed only smallensemble groups. The average size of the courtyard spacewas 22.4 m wide by 26.8 m long. Figs. 1 and 2 show thefloor plans and sections of the three theaters. The floor

plan of the theater was generally rectangular, yet thecourtyard space was not necessarily defined by surround-ing walls or galleries.

Theater FS contained a simple rectangular courtyard withan asymmetrical layout. Three sides of the courtyard werestraight, with covered galleries leading to the one-story mainhall. A winding bridge against rock piles occupied theother side and pushed the hall and stage off the centralaxis. About one-third of the ground in theater JM con-sisted of an abundant amount of rock with passages andvegetation. The two-story-high rock piles, rather than thewall behind them, defined the rear border of the courtyard.As was common in Chinese gardens, a major water poolcovered a significant ground area in theaters JM and FS(Figs. 3 and 4). The highly sound-reflective water surfaceoffered strong ground reflections. In theater PD a two-storymain hall and 1.6-m-high sidewalls that extended towardthe stage defined the courtyard (Fig. 5). The stage wasinside a larger yard filled with trees and scrubs, the yardbeing defined by an outer set of walls.

The buildings were generally constructed of wood. Thecolumns, beams, walls, and ceilings of the stages werewood and the floors were solid stone slabs (Fig. 6). Thesurrounding courtyard walls were made of earth sand-wiched between boards and then plastered. The doors andwindows in the walls of theater JM and PD were of a vari-ety of shapes. This produced sound penetration at theopenings and diffraction around the edges. Both thegallery ceilings and the walls in theater FS were made offlat plastered surfaces without openings. Rock piles, wind-ing bridges, statues, plants, stools, water vases, and deco-rations on window frames and ceilings diffused the sound.The literature reported diffusion in the frequency range of1000–2000 Hz bands for wooden decoration [14]. Thinwood paneling and glazing on the door might cause signif-icant resonance, absorbing low- and midfrequency sounds.

Modern four-story apartment buildings were builtbehind two surrounding galleries in theater FS. It is diffi-cult to determine exactly how these buildings affect thetheater acoustics. Apparently the facades might introduce

Table 1. Architectural dimensions of three theaters.*

Jixiao Manor, Pavilion for Drama, Fangchien Studio,He Yuan, Yangzhou Lin Family Residence Lin Family Residence

(JM) (PD) (FS)

Construction Date 1884 1853 1853

CourtyardAverage width (m) 26.7 18.7 (45.6)† 21.7Average length (m) 33.7 20.4 26.3

StagePlatform area (m2) 42.3 34.8 16.8Platform height (m) 0.5 0.0 0.0Ceiling height (m) 4.4 3.0 3.4Distance from back wall (m) 7.9 4.2 4.4

* Width and length of courtyard were calculated between surrounding walls. Platform height was platformfloor height relative to gallery floor. Length of theater JM was measured up to rock pile. Distance fromback wall was measured from line between two rear stage columns.† Width of outer set of walls.

CHIANG ET AL. ENGINEERING REPORTS


Fig. 1. Plan views of three theaters at the same scale. (a) Jixiao manor, He Yuan (JM), (b) Pavilion for Drama, Lin Family Residence(PD), (c) Fangchien Studio, Lin Family Residence (FS).

(c)

CL

18

17

20

19

16

15

11 12 13 14

(b)

RC

L

11 12 13

14 15

(a)

C R

LF

27

17

13

14 24

0 1 3 6 10 15

5 0 10 20 m



some late reflections. Noise might be another issue, espe-cially when an electronic sound system is used in this typeof theater. The audiences would be limited to the courtyardsince the platform is not raised and water pools, rocks,plants, and the other outdoor fixtures occupy the courtyardarea. For early reflections the occupied condition isexpected not to differ form the unoccupied condition.

2 INSTRUMENTS

The Environmental Research Group at the NationalTaiwan University of Science and Technology developedthe measurement system. A 0.34-s linear-sweep sine wave(sweeping up to 8000 Hz) was played through an omnidi-rectional loudspeaker (B&K 4295) at a height of 1 m.

Fig. 2 Longitudinal sections of three theaters at the same scale. (a) Jixiao manor, He Yuan (JM), (b) Pavilion for Drama, Lin FamilyResidence (PD), (c) Fangchien Studio, Lin Family Residence (FS).

(c)(b)

(a)

5 0 10 20 m

Fig. 3. Jixiao manor (JM). Fig. 4. Fangchien Studio (FS).



Monaural signals at a height of 1.2 m were recorded usingomnidirectional microphones (B&K 4192) and werecross-correlated with the stimulus to derive the impulseresponses (2.0 s long). Signal processing was performedusing a Hypersignal-Acoustic software package on anoctave-band basis. Due to noise from tourists, insects, andbirds, the impulse responses were averaged from repeatedmeasurements taken in the field (four on the stage and eightin the audience). The signal-to-noise ratio of the 1-kHzband was in the range of 35–54 dB, depending on thesource–receiver distance and the amplitude of environ-mental noise.

Widely used acoustical measures were calculated,including reverberation time (RT), early decay time(EDT), strength factor (G), clarity factor (C80), early sup-port (STE), and late support (STL). Table 2 summarizes thedefinitions of the measures used in this engineering report.EDT is considered more meaningful than RT for this studybecause of the absence of a roof in courtyard-type the-aters. Two other measures, echo criteria (EK) and tempo-ral diffusion (TD), were included to evaluate acousticaldefects.

Two source locations on the platform were used. The cen-ter source (source C) was on the central axis, 3 m from thefront edge, and the right source (source R) was 0.5 m off theaxis and 2 m from the front edge. There is an extra platformin front of the stage in theater JM, requiring a front source.Only the center source was used in theater FS, where theplatform area was less than half that of the others.

In theater FS all receivers were located at the surrounding

galleries and the bridge. In theater JM receivers were at bothside galleries and in the water front area on the left-handside. In theater PD the receivers were at the courtyard fac-ing the stage and at the main hall gallery. Except for fourreceivers in theater FS, all source–receiver distances wereless than the 20 m used today as a design goal for theaters.The early and late support measurements were taken onthe platform with a microphone 1 m away from the source.The absolute energy level for this measurement was usedto calibrate the loudspeaker output level where the electricpower may vary from theater to theater.

3 MEASUREMENT RESULTS

The average midfrequency RT and the EDT were 0.81and 0.74 s, respectively (Fig. 7). The corresponding mid-frequency clarity factor (C80) was 5.9 dB (Fig. 8). Whilethe midfrequency EDT was nearly similar to the RT intheaters JM and FS, the EDT was only 82% of the RT intheater PD. This can be attributed to the outer wall loop,which provided a longer late decay. Besides, the averageEDT (0.82 s) for theaters JM and FS with covered gal-leries was higher than that for theater PD (0.60 s), wherethe courtyard was surrounded by walls. Moving the sourcefrom the C position to the R position caused a 0.06-sdecrease in EDT while the average difference in thestrength factors G between the two sources was extremelysmall. Overall, the theaters measured were slightly dry forChinese traditional opera according to Xiang’s suggestion.Nevertheless, great speech intelligibility would be pro-vided with adequate loudness as the prerequisite.

The analysis showed an average strength factor G of 4.7dB for sources C and R, which was nearly 3 dB smallerthan the average G of three typical theaters in temples andguildhalls (Fig 8) [14]. This can be attributed to the raisedposition and the back walls for the stages in temples andguildhalls which provide strong early reflections to thereceivers. It might also be due to the openings in the sur-rounding walls of theaters JM and PD.

The frequency variation of RT was small, except for aslight drop in the 2000-Hz band. Diverse frequency char-acteristics of EDT were found for individual theaters. Thelow-frequency EDT for theater FS was high, which mightbe the result of rock piles and masonry materials. The

Fig. 5. Pavilion for Drama (PD). Fig. 6. Ceiling of Pavilion for Drama.



Table 2. Acoustical measures calculated for three theaters.*

Acoustical AssociatedMeasure Symbol Unit Subjective Aspect Mathematical Expression

Reverberation time RT s Reverberation clarity

Early decay time EDT s Reverberation clarity

Clarity factor C80 dB Clarity

Strength factor G dB Loudness

Early support STE dB Ease of ensemble

Late support STL dB Support

Echo criteria EK — Echo

Temporal diffusion TD — Coloration and fluttering

* E(t1, t2) — energy within time window t1 to t2.

RT 3(t– 5 – t– 25)where tx is the time corresponding to the x-dB point onthe decay curve R(t) and

,

,log

ms

msR t

E

E t10

0 2000

2000^

^

^h

h

h

EDT 6t– 10

,

,log

ms

msC

E

E10

80 1000

0 8080

^

^

h

h

,

,log

ms

msG

E

E10

0 10

0 100020

m1^

^

h

h

,

,logST

ms

ms

E

E10

0 10

20 100E

^

^

h

h

,

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ms

ms

E

E10

0 10

100 1000L

^

^

h

h

max∆ τ

EKms

ts

14

J

L

KK

^N

P

OO

h

where

τtsd

d

f p t t

f p t t t

τ

τ

0

0^

^

^h

h

h

for music sound and p(t) denotes impulse response

τ

φ

φTD

0

gg

gg 0

l

l

^

_

h

i

where ,τ τ τ τφ φ φwithbgg gg ggl ^ ^ ^ ^h h h h beingthe autocorrelation of the impulse response and τb ^ hthe weighting function

0

1.2

125 250 500 1 k 2 k

Octave band center frequency (Hz)

s

Fig. 7. Reverberation time RT (—) and early decay time EDT(- - -) as a function of frequency band for theaters JM ( ), PD ( ),and FS ().

-5

10

125 250 500 1 k 2 k


dB

Fig. 8. Strength factor G (—) and clarity factor C80 (- - -) as afunction of frequency band for theaters JM ( ), PD ( ), and FS().



2000-Hz-band G for the three theaters was 1.0 dB lessthan the midfrequency value. The slightly lower EDT andG values in the 2000-Hz band might be associated withthe diffusion provided by the wooden decorations of thebuildings and the vegetation inside the courtyards.

The largest G value (6.7 dB) was found in theater FS,where the courtyard space was the smallest and theperimeter walls were solid. Conversely, the large court-yard space and openings in the surrounding walls causeda low G (3.1 dB) in theater JM. However, the average G intheater JM increased to 4.1 dB when source F was used,indicating that the stage ceiling did not make significantcontributions to the early reflections. The source-averagedG values for half the receivers in theater JM were less than4 dB, a minimum value suggested for western chambermusic [10]. In theaters JM and PD, where courtyardgrounds were available, the G for the courtyard was nearly3 dB less than the G for the covered gallery (Fig. 9).

The average STE value was –9.3 dB in 250–2000-Hzbands, the frequency range comparable to most publisheddata. The high STE value can be attributed to the low 3.6-mceiling height (Fig. 10), although without a back wall

behind the stage, the average STE was not less than that ofthe previously mentioned theaters in temples and guild-halls, where the average ceiling height was greater [14].The average STL value was –19.8 dB, but the dispersionwas significant. In theater JM with two-story galleries,STL was as high as –17.8 dB.

The average (500-Hz to 2-kHz band) temporal diffusionTD was 0.082, which is significantly greater than the crit-ical value of 0.06. This can be attributed to the smoothnessof the plaster surfaces, which provide specular reflectionsto the receivers inside the galleries. The average value atthe receivers outside the surrounding galleries was there-fore smaller (0.077). Fig. 11 shows the significantreflected energy arrived before the 10-ms delay for thereceivers in theaters JM and FS. It is difficult to determinehow much sound fluttering occurs between the parallelwalls in the rectangular shapes that contributes to thesound coloration because there were irregularities on atleast one side of each pair of parallel walls in all threecases. The TD was also smaller than average in theater JM(0.078) due to the rock piles and the splaying of walls onthe left-hand side.

0

5

10

5 10 15 20 25

Source-receiver Distance (m)

Stre

ngth

Fac

tor

(dB

)

Fig. 9. Midfrequency strength factor G as a function ofsource–receiver distance comparing receivers inside coveredgallery () and in courtyard ( ) for theaters JM and PD. Twolines represent logarithm fits of data points.

-25

-5

125 250 500 1 k 2 k


dB

Fig. 10. Early support STE (—) and late support STL (- - -) as afunction of frequency band for theaters JM ( ), PD ( ), and FS().

Fig. 11. Midfrequency strength factor G as a function of source–receiver distance comparing theoretical values (—) for direct com-ponent to measured values integrated up to 10 ms after direct sound in theaters JM ( ), PD (), and FS ().

-10

-5

0

5

10

5 10 15 20 25

Source-receiver Distance (m)

dB



THE AUTHORS

Echoes would not be a potential problem because theaverage echo criterion EK was as low as 0.66 (comparedto the critical value of approximately 1.0). Nevertheless,EK was 0.81 at receiver 21 in theater FS. This can beattributed to the 90º corner in the gallery with the smoothplaster wall and ceiling, which provided multiple specularreflections with a significant delay.

4 CONCLUSIONS

Acoustical measurements were taken in three tradi-tional theaters integrated with Chinese gardens. In theirarchitectural forms these theaters were more irregular thanthe courtyard-type theaters inside temples and guildhalls.The ground of two theaters was covered with a sound-reflective water pool. The subjects studied included onetheater in He Yuan, China, and two at the Lin FamilyResidence, Taiwan.

The average midfrequency reverberation time RT andearly decay time EDT were 0.81 and 0.74 s, respectively.The values for the two theaters with covered gallerieswere higher. The clarity factor C80 was as high as 5.9 dB,indicating good speech intelligibility if there is sufficientloudness. The 4.7-dB average strength factor G wassmaller than the strength factors measured in three tem-ples and guildhalls reported in the literature. High tempo-ral diffusion (TD) values showing perceivable sound col-oration or even image shift can be attributed to the earlyreflective energy that arrived shortly after the direct sound.The risk of perceiving echoes was low. With most of theaudiences located in the surrounding galleries, theexpected occupied condition would not be greatly differ-ent from the unoccupied condition.

5 ACKNOWLEDGMENT

Funding for this study was provided by the NationalScience Council of the Republic of China under grantNSC 90-2411-H-011-001 and their support is gratefullyacknowledged. Particular thanks go to Teamwork Inc. fortechnical support with audio equipment.

6 REFERENCES

[1] B. Liao, The History of Ancient Chinese Theaters(in Chinese) (Chung Cho, Chengcho, 1997).

[2] J. Q. Wang, “Acoustics of Chinese TraditionalTheaters,” presented at the First Pan-American/IberianMeeting on Acoustics, Cancun, Mexico (2000 Dec.).

[3] J. Q. Wang, “A Primary Study of the Acoustics ofChinese Traditional Theatrical Buildings” (in Chinese),Tech. Acousti., vol. 21, no. 1/2, pp. 74–79 (2002).

[4] D. Xiang, Practical Architectural Acoustics (inChinese) (China Building Industry, Beijing, 1992).

[5] P. Kyoungsoo and K. M. Sung, “Criteria for KoreanTraditional Music Hall,” in Proc. WESTPRAC VII(Kumanmoto, Japan, 2000), pp. 1001–1004.

[6] D. Cheng, Chinese Music Instrument (in Chinese)(Sheng Yun, Taipei, 1985).

[7] C. Wang, Guildhall Theaters and Drama (inChinese) (Wen Jing, Taipei, 2000).

[8] Y. Hsu, W. Chiang, J. Tsai, and J. Wang,“Acoustical Measurements of Courtyard-Type TraditionalChinese Theater in East China,” presented at the AES21st International Conference for Architectural Acousticsand Sound Reinforcement, St. Petersburg, Russia (2002June).

[9] R. Richardson and B. M. Shield, “AcousticMeasurement of Shakespeare’s Globe Theater, London,”presented at Forum Acusticum 99, Berlin, Germany (1999Mar.).

[10] M. Barron, Auditorium Acoustics (E & FN Spon,London, 1993).

[11] J. Charles, Chinese Garden (Academy Editions,London, 1978).

[12] C. Lee, Lin Family Residence at Panchiao (HsiungShih Art Books, Taipei, 1987).

[13] Y. Tseng, Traditional Taiwan Drama (in Chinese)(Tong Hwa, Taipei, 1997).

[14] J. Tsai, “Acoustic Measurement of Courtyard-Type Traditional Chinese Theater” (in Chinese) Master’sthesis, National Taiwan University of Science andTechnology, Taipei (2002).

Jinjaw Tsai received a B. Arch. degree from theChung Yuan Christian University and an M. Arch. degree

from the National Taiwan University of Science andTechnology. Both his graduate design project and mas-

J. Tsai J. Wang L.-P. Xue

COMMENTS ON “HISTORY OF SPATIALCODING”*

In the above article1 I read, “The godfather of quadmatrix systems was Peter Scheiber, who established mostof the basic principles of matrix systems then and since.”

The article went on: “A system described in 1971 byShiga, Okamoto, and Cooper… used a diamond-patternmatrix: center front, left, right, and a mono surround chan-nel, presaging the later Dolby MP matrix system.” In fact,two years earlier (1969), I had filed a patent application onthe diamond-pattern matrix; the resulting patent no.3,632,886 was actually licensed to Dolby for its cinemaand consumer matrix systems. Dolby took a royalty-bearinglicense under this, and others of my patents, for motionpicture use in 1983, for consumer use of the patent’smatrix claims in 1984, and for consumer use of their logicclaims in 1986.

The 1984 license gave Dolby the right to sublicense thebasic matrix only, because the first consumer MP matrix(later, “Dolby Surround”) decoders had no logic. In 1985Dolby’s then vice president of licensing, Ian Hardcastle,wrote me a letter which included, “We are not at presentoffering any specific matrix enhancement technology toour licensees… If, at some time in the future, we developor acquire rights to a specific matrix enhancement circuitthat we wish to license to our licensees and if that circuitinfringes the directional enhancement claims of yourpatents, we would wish to reopen discussions at thattime.” In 1986 Dolby requested the right to license itslicensees under the “directional enhancement” (logic)claims of the patents. An amendment to Dolby’s licensegranting that right was signed in November of that year(“An agreement has been reached between DolbyLaboratories and Audiodata Company permitting Dolby to

sublicense high-separation logic decoding technology tomanufacturers of consumer Dolby SurroundTM equipment.Peter Scheiber of Audiodata holds several patents on thetechnology. He is a fellow of the AES.” — JAES, 4/87).Shortly after the 11/86 signing, Dolby’s corporatechronology for January 1987 reported, “First Dolby ProLogic directional enhancement surround decoder shownat CES.”

Original matrix/logic multichannel was a solution to therealities of the 1970s and 1980s, when programs had to besqueezed into the two audio-bandwidth channels of avail-able delivery media (vinyl disc, analog optical sound-tracks, VHS tape). In the 1990s, with the advent of widerbandwidth digital delivery media and practical real-timeaudio DSP, the spotlight swung over to discrete mediausing digital data compression. But the recent introductionof several brands of “next generation” matrix/logic sys-tems2 (Dolby’s Pro Logic II, SRS Labs’ Circle Surround,DTS’s Neo 6) confirms that the 30-year-old technologyoptimally meets certain market needs. It is telling that ProLogic II was introduced in 2000 as a decoder for the exist-ing Dolby Surround program, but later, encode/decodeversions were added for game developers and TV broad-cast (e.g., DP563 encoder, DP564 decoder).

PETER SCHEIBER, AES Life [email protected]

WHY IS BASS REPRODUCTION FROM ADIPOLE WOOFER IN A LIVING ROOM OFTENSUBJECTIVELY MORE ACCURATE THAN FROMA MONOPOLE WOOFER?**

There is anecdotal evidence that the 30–200 Hz fre-quency range is reproduced with less masking by the roomwhen dipole-type woofers are used, than with standardclosed-box or vented woofers. Very few commercial loud-speakers employ dipole bass, but there are a number of


ter’s thesis were on Chinese traditional operas and the-aters. He is currently in the military service in Taiwan.

Jiqing Wang (aka Chi-ching Wong) is a professor ofacoustics at the School of Science and a professor ofarchitecture at the School of Architecture and UrbanPlanning, Tongji University, Shanghai, China. He is a fel-low of the Acoustical Society of China and the AcousticalSociety of America. He is an author and a co-author offour books on architectural acoustics published in theChinese language. He and his colleagues translated into

the Chinese language the books Concert Halls & OperaHouse (L. L. Beranek) and Sound ReinforcementEngineering (W. Ahnert and F. Steffen) in 2002.

Lin-Ping Xue is a Ph.D. student at the Tongji University,China. He recently finished studying traditional theatricalarchitecture of the Ming dynasty in Shanxi province.

The biographies of Weihwa Chiang and Yenkun Hsuwere published in the 2003 October issue of the Journal.


* Manuscript received 2003 July 21.1 M. F. Davis, J. Audio Eng. Soc. (Features), vol. 51, pp.

554–569 (June 2003).2 “Next Generation of Dolby Surround Pro Logic Decoding,

Pro Logic II, Is Officially Announced,” www.dolby.com/com-pany/chronology (6/00).

**Manuscript received 2003 August 19; revised 2003September 4.



hobbyists who have built dipole woofers from plans3, 4 whoare enthusiastic about their sonic benefit. A search on theInternet for forum sites dealing with do-it-yourself loud-speaker design and dipole woofers can substantiate thisobservation.

The dipole has a figure-of-eight polar response in freespace and is essentially a velocity source, whereas amonopole is omnidirectional and a pressure source.Clearly, a dipole woofer excites room modes to a differentdegree when placed in the same location as a monopole.In general, the dipole couples strongly to room modes atlocations of high particle velocity, where the sound pres-sure is low, and when its free-space axis of radiation isaligned with the direction of mode propagation. Due to thedirectionality of a dipole source, it excites modes mini-mally that travel orthogonal to its main axis. Thus even forfixed dipole and monopole locations a dipole can poten-tially reproduce bass with less room participation.

Fewer modes are excited by a dipole [1]–[7], but thereis no agreement as to the perceptual consequences. Someauthors argue that a smoother frequency response can beobtained by proper orientation and location of the dipolesource [2], [5], [6], or that less energy is coupled intomodes [4], [7] and that this leads to greater clarity of bassreproduction. By contrast other authors argue that the lessuniform excitation of modes is detrimental [1], [3]because it increases the irregularity of the low-frequencyresponse.

Uniformity of the steady-state low-frequency roomresponse curve appears to be the generally accepted crite-rion for optimum bass reproduction. Many articles havebeen written about the optimum number and location ofwoofers for home theater installations and how to excite amaximum number of modes evenly. In all cases the targetis a smooth looking low-frequency response curve. Such arelativity smooth response is still far from a flat response,because of the many underlying resonances. Thisapproach leads to a large “quantity” of bass with littleirregularity, but it does not provide the highest “quality”reproduction. Bass notes are slow to decay when energyhas been stored in discrete room resonances, bass linearticulation is lost, and the sound drones on.

I have investigated possible reasons for the qualitativedifference between monopole and dipole bass reproduc-tion by in-situ measurements [4] and scale-model experi-ments. I am convinced that the steady-state low-frequencyresponse is a poor indicator of the quality of bass repro-duction, other than to point to the one or two modes thatneed to be equalized. The strongest correlation betweenmeasured data and subjective impression appears to comefrom a modulation-transfer-function measurement whichis analyzed in the time domain. For example, when ashort length of a 100% amplitude-modulated signal witha carrier-to-modulation-frequency ratio of 10:1 is used asstimulus, then the room response reduces the depth ofmodulation and increases the burst duration for different

frequencies and room locations. A pattern seems to appearwhereby the modulation envelope is subjectively pre-served more frequently with a dipole than a monopole.This correlates strongly with the impression that bassreproduced by a pair of dipole woofers is more articulateand thus more realistic of the recorded source.

As a hypothesis, consider that the combination of threeeffects might explain the bass clarity of dipole woofers.

1) A dipole’s directional polar response excites fewerroom modes.

2) Its total radiated power is 4.8 dB less than that of amonopole for the same on-axis SPL. Thus the strength ofthe excited modes is less.

3) A 4.8-dB difference in SPL at low frequencies is quitesignificant, due to the bunching of the equal-loudness con-tours at low frequencies, and is more equivalent to a10-dB difference in loudness at 1 kHz.

I would hope that further investigations into bass repro-duction in small acoustic spaces will lead to a deeperunderstanding of the physical and psychoacoustic param-eters that determine the perceived sound quality.

REFERENCES

[1] T. Salava, “Comments on ‘Dipole LoudspeakerResponse in Listening Rooms’ and ‘Perception ofReverberation Time in Small Listening Rooms,’ J. AudioEng. Soc., (Letters to the Editor), vol. 51, pp. 248–250(2003 Apr.).

[2] J. M. Kates, “Dipole Loudspeaker Response inListening Rooms,” J. Audio Eng. Soc., vol. 50, pp.363–374 (2002 May).

[3] E. R. Geddes, “On Sound Radiation from PortedEnclosures,” J. Audio Eng. Soc., vol. 49, pp. 117–124(2001 Mar.).

[4] S. Linkwitz, “Investigation of Sound-QualityDifferences between Monopolar and Dipolar Woofers inSmall Rooms,” presented at the 105th Convention of theAudio Engineering Society, J. Audio Eng. Soc.(Abstracts), vol. 46, p. 1032 (1998 Nov.), preprint 4786.

[5] C. Ferekidis and U. Kempe, “Room ModeExcitation of Dipolar and Monopolar Low-FrequencySources,” presented at the 100th Convention of the AudioEngineering Society, J. Audio Eng. Soc. (Abstracts), vol.44, p. 639 (1996 July/Aug.), preprint 4193.

[6] B. Tsakiris, A. Sdravopoulos, and S. Salamouris,“Finite Baffle Dipole Loudspeakers with ElectrodynamicDrivers: Designs, Implementation, Measurement, and anExperiment of Digital Equalization,” presented at the100th Convention of the Audio Engineering Society, J.Audio Eng. Soc. (Abstracts), vol. 44, pp. 636, 638 (1996July/Aug.), preprint 4184.

[7] S. Linkwitz, “Development of a Compact DipoleLoudspeaker,” presented at the 93rd Convention of theAudio Engineering Society, J Audio Eng. Soc. (Abstracts),vol. 40, p. 1055 (1992 Dec.), preprint 3431.

SIEGFRIED LINKWITZ

Linkwitz LabCorte Madera, CA 94925, USA

3Dipole prototypes, http://www.linkwitzlab.com/proto.htm.4Dipole woofer construction http://www.linkwitzlab.com/

woofer.htm.

STANDARDS IN PRINTThe AES publishes many standards, reports, and infor-mation documents on a range of audio topics. These are reg-ularly reviewed and maintained to keep them current. Newdocuments are developed by the AES Standards Committeewhere a need is identified and technical expertise isavailable. AES standards reflect a general consensus estab-lished through the open public process of the AESSC.

Here is a summary of currently published documents:

STANDARDS

AES2-1984 (r2003)* AES Recommended Practice—Specification of loudspeaker components used inprofessional audio and sound reinforcement

AES3-2003 AES Recommended Practice for DigitalAudio Engineering—Serial transmission format for twochannel linearly represented digital audio data

AES5-1998 AES Recommended Practice for ProfessionalDigital Audio—Preferred sampling frequencies forapplications employing pulse-code modulation

AES6-1982 (r2003) Method for measurement of weightedpeak flutter of sound recording and reproducing equipment

AES7-2000 AES Standard for the Preservation andRestoration of Audio Recording—Method of measuringrecorded fluxivity of magnetic sound records at mediumwavelengths

AES10-2003 AES Recommended Practice for DigitalAudio Engineering—Serial Multichannel Audio DigitalInterface (MADI)

AES11-1997 AES Recommended Practice for DigitalAudio Engineering—Synchronization of digital audioequipment in studio operations

AES14-1992 (r1998) AES Standard for ProfessionalAudio Equipment—Application of connectors, part 1,XLR-type polarity and gender

AES17-1998 AES Standard Method for Digital AudioEquipment—Measurement of digital audio equipment

AES18-1996 (r2002) AES Recommended Practice forDigital Audio Engineering—Format for the user datachannel of the AES digital audio interface

AES20-1996 (r2002) AES Recommended Practice forProfessional Audio—Subjective evaluation of loudspeakers

AES22-1997 (r2003) AES Recommended Practice forAudio Preservation and Restoration—Storage of polyester-based magnetic tape

AES24-1-1998 (AES24-1-1995) AES Standard for SoundSystem Control—Application protocol for controlling andmonitoring audio devices via digital data networks—Part1: Principles, formats, and basic procedures.

AES24-2 1999 AES Standard for Sound SystemControl—Application protocol for controlling andmonitoring audio systems—Part 2: Class tree

AES26-2001 AES Recommended Practice for ProfessionalAudio—Conservation of the polarity of audio signals

AES27-1996 (r2002) AES Rrecommended Practice forForensic Purposes—Managing recorded audio materialsintended for examination

AES28-1997 (r2003) AES Standard for AudioPreservation and Restoration—Method for estimating lifeexpectancy of compact discs (CD-ROM), based on effectsof temperature and relative humidity

AES31-1-2001 AES Standard for Network and FileTransfer of Audio—Audio-file transfer and exchange—Part 1: Disk format

AES31-3-1999 AES Standard for Network and File Transferof Audio—Audio-file transfer and exchange— Part 3: Simpleproject interchange including maintenance of annex F.

AES33-1999 AES standard procedure for maintenance ofAES audio connector database.

AES35-2000 AES Standard for Audio Preservation andRestoration—Method for estimating life expectancy ofmagneto-optical (M-O) discs, based on effects oftemperature and relative humidity

AES38-2000 AES Standard for Audio Preservation and


COMMITTEE NEWSAES STANDARDS

Information regarding Standards Committee activi-ties including meetings, structure, procedures, re-ports, and membership may be obtained viahttp://www.aes.org/standards/. For its publisheddocuments and reports, including this column, theAESSC is guided by International ElectrotechnicalCommission (IEC) style as described in the ISO-IECDirectives, Part 3. IEC style differs in some respectsfrom the style of the AES as used elsewhere in thisJournal. For current project schedules, see the pro-ject-status document on the Web site. AESSC docu-ment stages referenced are proposed task-groupdraft (PTD), proposed working-group draft (PWD),proposed call for comment (PCFC), and call forcomment (CFC).


AES STANDARDSCOMMITTEE NEWS

Restoration—Life expectancy of information stored inrecordable compact disc systems—Method for estimating,based on effects of temperature and relative humidity

AES41-2000 AES Standard for Digital Audio—Recodingdata set for audio bit-rate reduction

AES42-2001 AES Standards for Acoustics—Digitalinterface for microphones

AES43-2000 AES Standard for Forensic Audio—Criteriafor the authentication of analog audio tape recordings

AES45-2001 AES Standard for Single ProgrammeConnectors—Connectors for loudspeaker-level patchpanels

AES46-2002 Standard for Network and File Transfer ofAudio—Audio-file transfer and exchange—Radio trafficaudio delivery extension to the broadcast-wave-file format

AES47-2002 Digital audio in asynchronous transfer mode(ATM)

INFORMATION DOCUMENTS

AES-1id-1991 (r2003) Plane-wave tubes: design andpractice

AES-2id-1996 AES Information Document for DigitalAudio Engineering—Guidelines for the use of the AES3interface

AES-3id-2001 AES Information Document for DigitalAudio Engineering—Transmission of AES3 formatteddata by unbalanced coaxial cable

AES-4id-2001 AES Information Document for RoomAcoustics and Sound Reinforcement Systems—Characterization and measurement of surface scatteringuniformity

AES-5id-1997 (r2003) AES Information Document forRoom Acoustics and Sound-Reinforcement Systems—Loudspeaker modeling and measurement—Frequency andangular resolution for measuring, presenting and predictingloudspeaker polar data

AES-6id-2000: AES Information Document for DigitalAudio—Personal computer audio quality measurements

AES-10id-1995 (r2000) AES Information Document forDigital Audio Engineering—Engineering guidelines for themultichannel audio digital interface (MADI) AES10

PROJECT REPORTS

AES-R1-1997 AES Standards Project Report—Specifications for audio on high-capacity media

AES-R2-1998 AES Standards Project Report for Articleson Professional Audio and for Equipment Specifications—Notations for expressing levels

AES-R3-2001 AES Standards Project Report—Compatibility of tip-ring-sleeve connectors conforming todifferent standards

AES-R4 2002 Guidelines for AES Standard for DigitalAudio—Digital input-output interfacing—Transmission ofdigital audio over asynchronous transfer mode (ATM)networks, AES47

Notes:

*The notation (r2003) indicates document reaffirmationduring 2003.

Further information, including access to documents andinformation about participation, can be found athttp://www.aes.org/standards/.

THEPROCEEDINGS

OF THE AES 23RD

INTERNATIONALCONFERENCE

Signal Processing in Audio Recording and Reproduction

2003 May 23 –25Copenhagen, Denmark

You can purchase the book and CD-ROM online at www.aes.org.

For more informatione-mail Andy Veloz at

[email protected] or telephone+1 212 661 8528 x39.

291 pages

These 22 papers focus on sound recording andreproduction from microphone to loudspeaker, includ-

ing the interaction between loudspeaker and room.


INTRODUCTIONThe idea of using head-related or bin-aural signals to generate a three-dimensional spatial rendering of anauditory scene is not a new concept.So-called binaural audio technology(it can be argued that all spatial audiois ultimately binaural at the point ofhuman reception) has been researchedfor many years and has remained ofperennial interest to the academic andresearch communities because of itstheoretical capacity to deliver full 3-Drepresentations of a sound field, withall the spatial cues intact. It has, how-ever, only recently become more com-mercially important as increased use ismade of enhanced 3-D audio repro-duction in applications such as virtualreality (VR).

In traditional binaural applicationshead-related signals are either capturedor synthesized, then delivered to thetwo ears of the listener using head-phones (enabling the separate deliveryof the two signals to the relevant ears)or using loudspeakers with appropriatecrosstalk cancelling (so as to achievetechnically similar results but requiringthe listener to adopt a limited range ofpositions in relation to the loudspeak-ers). Improvements to these approach-es have included the use of head-track-ing to enable the employment of headmovements in binaural signal synthe-sis, individualized and generalizedHRTFs (head-related transfer func-tions) that describe the signal transfercharacteristics between source andeardrum, and the addition of simulatedreflections and/or reverberation to drysignals so as to improve the sense of

externalization, naturalness, and space. Recent work, such as that described

here, has included the computer mod-eling of heads and torsos so as to en-able the study and simulation of dif-ferent HRTFs without the need formeasurements on physical heads. Ithas also involved improved methodsfor studying the localization perfor-mance of 3-D audio systems. The fu-ture holds interesting experiences inwhich 3-D audio may be integratedwith natural listening in the form of“wearable augmented reality” audiothat brings closer the science-fictionconcept of communication equipmentthat is integrated more completelywith the natural senses, perhaps in-volving audio implants that enable oneto hear both natural sounds and repro-duced sounds together.

MODELING AND BINAURALRESPONSES

Head-shape modeling based onspherical harmonics

Tao et al. describe an approach to thecomputation of head shapes using mod-els based on spherical harmonics intheir paper “A Study on Head ShapeSimplification Using Spherical Har-monics for HRTF Computation at LowFrequencies,” paper 5787 presented atthe AES 114th Convention. They showthat different parts of the head shape re-quire different numbers of sphericalharmonics to represent them accurately.They do this by measuring the errorfunction between a low-pass filteredmodel of a pinna-less KEMAR dummyhead (using lower-order spherical har-monics) and a reference model (us-

This article presents a digest of selected papers from recent AES conventions in the fieldof binaural or head-related spatial audio reproduction. It specifically excludes multi-channel recording and reproduction techniques and wavefield synthesis, which will becovered in a future article.

Fig. 1. Direction-averaged percentage pressure errors at 3 kHz against number ofspherical harmonics (courtesy Tao et al.).

*

* ** * * * * * * * * * * ** * * * ** ***

BINAURAL AUDIO IN THE ERA OFVIRTUAL REALITY

A digest of research paperspresented at recent AES conventions

Per

cent

age

pres

sure

err

ors

(%)

100

80

60

40

20

0 0 5 10 15 20 25 30 35n

Mono

Multichannel

Stereo

• Home Theater/Entertainment

• Wireless + Portable

• Telecom + Voice

• Gaming

• Internet + Broadcast

Technologies. Product Applications

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• VIP

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The Future of Audio. Technical information and online demos at www.srslabs.com2002 SRS Labs, Inc. All rights reserved. The SRS logo is a registered trademark of SRS Labs, Inc.C

Aiwa, AKM, Analog Devices, Broadcom, Cirrus Logic, ESS, Fujitsu, Funai,

Hitachi, Hughes Network Systems, Kenwood, Marantz, Microsoft,

Mitsubishi, Motorola, NJRC, Olympus, Philips, Pioneer, RCA, Samsung,

Sanyo, Sherwood, Sony, STMicroelectronics, Texas Instruments, Toshiba

SRS Labs is a recognized leader in developing audio solutions for any application. Its diverse portfolio

of proprietary technologies includes mono and stereo enhancement, voice processing, multichannel

audio, headphones, and speaker design. • With over seventy patents, established platform partnerships

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partner for companies reliant upon audio performance.


ing 34 harmonics). They restrict them-selves to frequencies no higher than 3kHz where pinna effects would normal-ly become more important.

The overall accuracy of the headshape appears to improve relativelyquickly as spherical harmonics areadded, but more detailed regions suchas around the nose require higher num-bers. They suggest that above about 10to 11 harmonics the error function doesnot decrease substantially in these re-gions, leading them to suppose thatthis might be adequate accuracyfor computational head models,at least up to a frequency of 3kHz or so. It is noted that thepressure at the ear position con-verges relatively quickly withthe reference as the number ofspherical harmonics increases,whereas the nose region takeslonger, with no significant re-duction beyond about 14 har-monics (see Fig. 1). The authorsgo on to discuss the relationshipbetween errors in head shapeand errors in the acoustic pres-sure on the surface of the headin different places, noting aclose correspondence betweenthe two factors.

A snowman head andtorso model

Algazi et al. in “The Use ofHead and Torso Models for Im-

proved Spatial Sound Synthe-sis” (paper 5712, AES 113thConvention) also concentrate onlow frequency modeling ofHRTFs, this time using a so-called snowman model of headand torso (see Fig. 2). They ex-plain that the effect of the torsois known to be quite importantin generating elevation and ex-ternalization cues in head-relat-ed stereophony, particularly theshoulder reflection. In fact theydescribe an earlier experimentin which the source spectrumwas limited to 3 kHz so as to re-move pinna-based elevationcues. Here they found that thelocalization performance wasessentially the same when anaccurately measured HRTF wasreplaced with a simple sphericalhead model augmented by re-

flections from an ellipsoid torso. Inthe experiments described in this pa-per the upper frequency of interestwas limited to 5 kHz.

In the snowman model the authorspropose an even simpler shape struc-ture based on two spherical objects,mainly because they lend themselvesto relatively simple representation us-ing digital filters. Three different com-putational approaches were investigat-ed for modeling: finite difference,boundary element, and multipole re-

expansion, with the latter appearing tobe favored. The authors were interest-ed in this simple modeling for low-fre-quency HRTFs because they had dis-covered that accurately measuredHRTFs are difficult to obtain at lowfrequencies for a variety of reasons,leading to inaccurate localization per-formance and poor LF response in bin-aural reproduction. Compensation forpoor LF response has been found to af-fect localization performance, andproblems arise, for example, with lo-calization of sources at low elevations.

In implementing suitable filters to rep-resent the effects of the snowman model, it was found that certain aspectsof the frequency response required somecompensation, particularly some bright-spot areas that gave rise to an exaggerat-ed HF response during informal listen-ing tests. The implemented filters,therefore, were a compromise betweenrepresenting the first-order effects of thesnowman model accurately and com-pensating for the timbral colorations re-sulting from an over-simplified HATSmodel. The filter model (see Fig. 3)switches between a torso-shadow modeland a torso-reflection model dependingon whether the source is inside or out-side the torso shadow cone pictured inFig. 2. IIR filters are used for simplicityinstead of the more common switchableor interpolated FIR filters. The authorsalso decribe a means by which these can

BINAURAL AUDIO IN THE ERA OF VIRTUAL REALITY

Fig. 2. The torso shadow cone, which isdefined as the set of rays from the ear that aretangent to the torso. A source outside thetorso shadow cone gives rise to a torsoreflection. A source inside the torso shadowcone is shadowed by the torso.

Fig. 3. Filter model for the snowman: (a) major components; (b) torso reflection submodel;(c) torso shadow submodel (Figs. 2 and 3 courtesy Algazi et al.).

Torso ReflectionSub-model

Torso ShadowSub-model

Torso Shadow Haed Shadow

HH(s, 0D)

HH(s, 0D)

HH(s, 0HS)HT(s, 0T)

X

X

X

Y

Y

Y

Direct Path

Torso Reflection Path

(a)

(b)

(c)

TR(ξ) TH(0R)

TH(0D)

TH(0HT)

P

+1

1+p


be changed arbitrarily and quickly with-out introducing transient artifacts, to en-able rapid source or head-positionchange simulation.

The question of how to combine orintegrate such snowman-modeled low-frequency HRTFs with measured high-frequency ones is considered. The au-thors conclude that the mostappropriate solution is to use the phaseresponse from the model and to cross-fade the magnitude response betweenmeasured and modeled values at lowfrequencies. This is because the phaseresponse of measured responses hasbeen found to be unreliable at LF andof little perceptual import at HF.

Binaural room impulseresponses

In “The Importance of Reflections in aBinaural Room Impulse Response”(paper 5839, AES 114th Convention),Jensen and Welti describe a project inwhich simplifications are sought in therepresentation of binaural room im-pulse responses (BRIRs). Such BRIRsare often used in synthesizing and ren-dering room acoustics, either based onreal room responses or on computermodels of rooms, for such applicationsas virtual reality and computer-aideddesign of room acoustics. There arenumerous individual reflections, earlyand late, in a typical BRIR, and theauthors suspected that many of themare in fact perceptually redundant—inother words, that they may be maskedwith typical source material.

Starting with research on the audibil-ity of reflections conducted by others,such as Haas, Jensen and Welti con-clude that there is still a need for fur-ther work applied to real-world appli-cations (such as theirs), rather than as ameans of studying underlying auditoryprocesses. It seems that the approachused was to add a synthesized reflec-tion to a prerecorded BRIR that hadbeen recorded in a real lecture room ina number of locations to determine thedetection level of the added reflection.They were interested in reflections inthe time zone following the immediateearly reflection region up to 15 ms.This resulted in reflections added at 15,30, 60, 100, and 200 ms, after which itwas supposed that the reflection tailbecame stochasticly determined. Theadded reflections were given their own

BRIRs using HRIR(head related impulseresponse) convolutionto synthesize specificdirections, and thesewere loudness scaledas required as well asadjusted slightly if theylanded on top of exist-ing reflections, therebycreating an artificiallynoticeable result.

In listening tests,during which bothnoise bursts andspeech signals wereused as source materi-al, they found that themasked threshold ofthe added reflectionswas considerably high-er for the speech thanfor the noise burst,making the noise bursta more critical item.They then proceededto use the maskedthreshold thus deter-mined as a basis for re-moving low-level (po-tentially masked)reflections in the initialBRIR, replacing themwith shaped whitenoise that was designed to match theoriginal reverberation characteristics inall senses except the location and levelof individual reflections. Interestingly,they found that for the voice signal upto 93% of the BRIR between 15 and200 ms could be replaced with only a10% detection rate, although for thenoise burst the detection rate was high-er. The matching of the spectral shapeof the signal used to replace the reflec-tions was a critical factor. The authorssuggest that the results may be evenmore satisfactory for less critical sig-nals such as music.

REPORTING LOCALIZATIONJUDGMENTSTwo papers from the 114th Conven-tion concentrate on novel approachesto localization judgment in 3-D audioexperiments. Traditionally a range ofdifferent means have been used togather information about the perceivedlocations of virtual sound sources, in-cluding pointing, drawing, head-point-

ing, verbal descriptions, and so forth.As explained by Kelly and Tew in “ANovel Method for the Efficient Com-parison of Spatialization Conditions,”(paper 5786), these methods all sufferfrom the problem of translating the au-dio–spatial image into a physical de-scription. They describe a means ofcomparative localization judgmentthat is based on the matching of twosound sources and is said to be rela-tively free from the need for costlyand time-consuming procedures. Thesystem they describe uses a graphicaluser interface that enables the user tomove a virtual audio source aroundthe head position, attempting to matchit to the position of a target sourcepanned using accurate HRIRs. It isalso possible to add distractor signalsto evaluate their effect on the mini-mum audible angle (MAA).

The authors found that very smallerrors in MAA were detectible usingthis approach and that front-back re-versals were easy to detect. They


Fig. 4. Some views of the 3-D display used to feed backreported source positions to the user (courtesy Pernaux et al.).

claimed that such small differencesmay be hidden in conventional abso-lute localization studies. The interfaceand the signals could be implementedon a relatively simple PC, which theyclaim lends itself to conducting wide-ranging studies using the Internet, forexample. Current implementations ap-pear only to handle horizontal locationat a specific distance, and the authorsdo not discuss the accuracy of the tar-get signal’s spatial synthesis method orhow that might affect comparisonswith other methods of spatial synthe-sis. However, they do comment on thepossibility that subjects might usematching of the spectral characteristicsof sources as a means of “getting itright,” rather than the spatial location,although they believe that the agree-ment between theirs and other studiesof the MAA refute this idea. In anycase, they say that the target signalcould be of a different nature to the testsignal if necessary.

Perneaux et al. in “Perceptual Evalu-ation of Binaural Sound Synthesis: TheProblem of Reporting LocalizationJudgments” (paper 5789, AES 114thConvention), offer a comprehensivereview of localization judgment meth-ods. They go on to describe the use ofa variety of novel interfaces developedby them for this purpose during devel-opment of binaural 3-D audio systems.Starting with a simple 2-D graphicalinterface showing side, back, and top

of the head, with mouse-pointing to in-dicate the source location, they thenadd a 3-D form of feedback that en-ables the listener to see the reportedsource location (see Fig. 4). A 3-Dlaser-scanned representation of theuser’s head is displayed, the cameraangle of which is adjusted so that thereported source position is always visi-ble. This allows the listeners to con-firm their reported position in relationto a representation of their own head inthree dimensions. A third method in-volved the use of tracked finger-point-ing, using a Polhemus stylus, enablingthe listener to point to the position ofthe source in relation to the head. Be-cause the sources were rendered with-out taking any account of head position(i.e., using static HRTFs) they wouldmove with the listener’s head as itmoved; so the authors used a headtracker to monitor the actual positionof the listener’s head as he pointed.This enabled them to plot the locationof the pointed source in relation to thecurrent head position.

Of the three methods, the last onewas found to be the most accurate withan average error on the front-back planeof 11 degrees. The 2-D method withoutthe 3-D display was the poorest, with anaverage error of 15 degrees. And the 2-D mouse pointing with 3-D feedbackachieved an average error of 12 degrees.In the up/down direction a similar resultwas found, although there was not very

much difference between the methods.The authors do not mention any differ-ences in the left-right direction. A morenoticeable difference was noted interms of response time, with the 3-Dpointing method being more than twiceas fast as the 2-D mouse method (7 sec-onds as opposed to 17). In conclusion,they note that some form of tactile stim-ulus could be used instead of an audito-ry stimulus as a means of reducing thereporting error, as tactile stimulus loca-tion judgment is supposed to be moreaccurate than that of the auditorymodality.

ADAPTIVE HEADPHONEREPLAYThe problem of headphone reproduc-tion has plagued binaural reproductionfor many years, partly because of thedifferences in matching to the individ-ual listener’s ears, resulting in mis-matches between the intended and ac-tual perception of spatial localization.Schobben and Aarts address this prob-lem in “Three-Dimensional Head-phone Sound Reproduction Based onActive Noise Cancellation” (paper5713, AES 113th Convention). Theydescribe a system by which the head-phone rendering can be improved forvirtualization of loudspeaker systems,such as in virtual home cinemas. Theyrelate the development of a techniquethat is based on the principle of activenoise cancelling. Two small micro-phones are placed inside the head-phones and used to monitor the soundpressure in the vicinity of each ear.

The calibration procedure appears torequire that the listener first sits in thesweet spot of the loudspeaker systemto be emulated. A noise signal is thensent to the loudspeakers and to theheadphones, with the microphonesmonitoring the sound pressure fromthe two to provide an input to an adap-tive filter that filters the headphonedrive in an attempt to minimize themicrophone signal. The adaptive fil-ter’s response should then be equal tothe loudspeaker-to-microphone trans-fer function times the inverse of theheadphone-to-microphone function.When this is achieved and the loud-speaker is turned off, there should beminimal difference between the loud-speaker sound and the headphonesound at that position, and the user


Fig. 5. Example of a WARA telepresence application in which one user isimmersed in the spatial auditory environment of the other (courtesy Härmä et al.).


is said to have the illusion of listeningto loudspeakers.

They found that in-ear headphonesfitted with tiny microphones weremuch more sensitive to calibration er-rors than full headphones. This wasmainly due to place–replace errors inthe in-ear headphone transfer responseand was found to be enough to destroythe 3-D sound image. Some of theproblems encountered with using thisapproach were related to the fact thatfull headphones tend to obstruct thesound from the loudspeakers duringcalibration, either owing to closedbacks or other reflective characteris-tics. However, a prototype headphonehas been developed that appears to per-form reasonably well in this respect.Furthermore, they found it necessary toemploy small tubes on the micro-phones to monitor the pressure closerto the ears (which could be removedafter calibration); the most successfulresults were found with the tube en-trance close to or even inside the earcanal. Based on these issues theyclaimed that good performance couldbe achieved up to a frequency of 7 kHzor so, largely dictated by the accuracyof location of the pressure-measuringmicrophones and tubes.

A TASTE OF THE FUTUREHärmä et al. provide a glimpse of the fu-ture in “Techniques and Applications ofWearable Augmented Reality Audio”(paper 5768, AES 114th Covnention).Augmented reality is something that hasuntil recently only been discussed in sci-ence fiction. But advances in wirelessand mobile communications are bring-ing it closer to reality. Such technologywill enable reproduced sounds to becommunicated to a mobile listener insuch a way thay they are blended with,thus augmenting, natural sounds. Theauthors have labeled this wearable aug-mented reality audio, or WARA.

We currently have a wide range ofdifferent mobile communication devicesand personal entertainment systems.Someday soon these may be combinedinto a single system with integratedfunctions connected to remote wirelessnetwork services. The sound reproducedby such a device could be managed sothat the user is still able to hear and in-teract with the natural environment, butwith enhanced cues such as those that

might help someone communicate in anoisy environment, for example, or pro-vide them with auditory displays of traf-fic information.

By incorporating microphones intominiature in-ear headphones, the soundof the natural environment is mixed withreproduced sounds using a so-calledaugmentation mixer. In-ear phones havethe advantage that they can block the earcanal more satisfactorily than openphones, enabling more control over thesignal reaching the ears. The authorsdemonstrate isolation of between 10 and30 dB from the outside world in prac-tice. Ideally augmented reality signalswould be perceived entirely naturally,passing the “Turing test” in which an ar-tificial signal cannot be distinguishedfrom a natural one. Because natural sig-nals are passed through a microphone/headphone system, leading to potentialdifferences from natural listening, theauthors currently refer to a pseudo-acoustic environment for natural sound.The HRTFs of the listener are disturbedby the use of microphones and ear-phones so their spatial hearing is affect-ed, but tests have shown that users arecapable of adapting to such circum-stances within a relatively short period.

Härmä et al. provide an interesting ex-ample of a “telepresence” application(see Fig. 5), in which one user could ex-perience the auditory environment of an-other by means of a real-time binauraltransmission. This has parallels withcurrent photo-messaging on mobilephones, except that it takes the experi-ence one step further to immerse the re-ceiving user in the spatial auditory worldof the other. They describe other appli-cations, such as auditory “post-it” notes,a calendar with reminders, and a binau-ral telephone that enables talkers to beexternalized rather then perceived insidethe listener’s head.

In a listening test using both open andclosed earphones, they found that mostlisteners found it impossible to distin-guish between virtual sounds and realsources reproduced from loudspeakershidden behind a curtain. They used theidealized case of in-situ HRIRs to virtu-alize the sources, but it demonstrates thepotential for seamless integration of realand virtual sounds in a way that heraldsa brave new world in which the bound-aries between the real and the not-so-real become hard to define.



2002 June 1–3St. Petersburg, Russia

You can purchase the bookand CD-ROM online at

www.aes.org. For informationcontact Andy Veloz at

[email protected] telephone

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THEPROCEEDINGSOF THE AES 21st

INTERNATIONALCONFERENCE

ARCHITECTURAL ACOUSTICSAND SOUND REINFORCEMENT

PRESIDENT

RON STREICHER has served as an officer of theAES on both thesection and i n t e r n a t i o n a llevels for morethan twenty-fiveyears. He hasbeen a gover-nor, regionalvice-president,

and since 1991 secretary of the Soci-ety. He is a fellow of the AES and in1995 was awarded the Bronze Medal“in recognition of his long standingdedication to the goals of the AES andfor continued work on its behalf.”

Ron has given numerous technicalpresentations at AES section meet-ings, conventions, and conferencesworldwide and twice been publishedin the Journal. He developed the his-torical series “An Afternoon With…”first in 1980 for the Los Angeles Sec-tion, and subsequently as a regularfeature of the Society’s West Coastconventions. As a further develop-ment, he produced the AES videotapeAn Afternoon With Jack Mullin. Healso produced the compact disc AESPresents Graham Blyth in Concert, acompilation of recordings from the organ recitals at the Society’s conven-tions. Streicher believes strongly inaudio education, and his book, TheNew Stereo Soundbook, Second Edi-tion (originally coauthored with F. Alton Everest), has been acceptedthroughout the world as a standardreference text on stereophonic tech-niques. Since 1988, he has been amember of the faculty of the Audio

Recording Institute and serves as audio production manager at the Aspen Music Festival and School.Continuing his lifelong involvementwith music, Ron is a freelance tonmeister, specializing in live musi-cal performances as well as radio dra-ma and documentaries.

.

PRESIDENT-ELECT

THERESA LEONARD is the directorof Audio for Mu-sic & Sound atThe Banff Cen-tre. She is re-sponsible foroverseeing theaudio work/studyprogram and di-recting activitiesat the centre’s

extensive audio facilities. Her workspans many aspects of audio production,administration, and engineering, includ-ing both studio and live recording andpostproduction in a variety of musicalgenres, as well as audio for video post-production. As director of The BanffCentre’s audio education program, sheworks closely with top industry person-nel, who serve as faculty members andguest lecturers. Leonard holds bachelordegrees in music and in education, and amaster’s degree in music from McGillUniversity, where she was enrolled inthe sound recording program. Her thesis, “Time Delay Compensation ofDistributed Multiple Microphones inRecording: An Experimental Evalua-tion” was later transcribed into an AESpaper and presented in New York Cityat the 95th Convention in 1993.

Trained as a classical pianist, she

previously taught music in French andEnglish schools in eastern Canada,worked as audio postproduction engi-neer for a Canadian TV series, and asan audio engineer and instructor at theUniversity of Iowa School of Music.She is the regional representative forthe Alberta Recording Industry Asso-ciation, a past member of the AESBoard of Governors, and founder andchair of the AES’ Alberta Section. Sheserved on the executive committee ofthe AES Convention in Los Angeles in2002, and as chair of the AES confer-ence on multichannel audio at TheBanff Centre in June 2003.

SECRETARY

HAN TENDELOO was born in Amsterdam, theNetherlands, in1936. He re-ceived his mas-ter’s degree inelectrical engi-neering from theTechnical Uni-versity of Delft,in the Nether-

lands, with a specialization in semicon-ductors. He has been employed byPhilips-related companies such as Poly-Gram and PDO in the fields of record-ing, duplication, replication and productdevelopment and marketing: LP, MC,VLP, CD, CD-i, CD-Video, DCC,packaging. He is coinventor of the CDjewel box. He was a long time chair ofNEC TC60 (IEC Audio and Video-Recording Standardization) and a mem-ber of the Society of Motion Picture andTelevision Engineers (SMPTE).

After his retirement he freelanced


AES Officers 2003-2004

NEW OFFICERS

for Philips and the International Feder-ation of the Phonographic Industry(IFPI) in London. An AES membersince the mid 60s, he has held the fol-lowing AES offices: vice president,Northern Region, Europe; governor;vice chair of the Standards Committee,Europe Region; chair and member ofthe Publications Policy Committee;convention chair; convention vicechair; and convention program coordi-nator. He was awarded a fellowship in1977 and has received three Board ofGovernors Awards. His focus in recenttimes is on improvement of informa-tion to the membership about upcom-ing AES conventions by introducingbar-graph convention calendars, com-prehensive semi-interactive conven-tion Web sites, and detailed on-siteconvention planners.

TREASURER

MARSHALL BUCK studied physicsand engineeringat the CaliforniaInstitute ofTechnology andreceived B.A.,M.A. and Ph.D.degrees fromUCLA, wherehe was a re-searcher in the

Computer Science Department. In1982, he formed Psychotechnology,Inc., providing expertise in loudspeak-er and electronic design; computer-aided measurement; acoustic and psychoacoustic research.

Buck served as chief engineer at Cer-win-Vega. From 1991 to 1997, he waswith Harman/JBL, as chief acoustic engineer for Harman Applied Tech-nologies; as chief of technical resourcesfor Harman International’s Researchand Development Group; and as vicepresident of engineering for HarmanOEM Group. He worked on activenoise and vibration control, linear actu-ators, objective and subjective testing,DSP and PC sound. He has been issuedseveral patents and presented papers onelectronic and electroacoustic devices.

Buck is a member of the HollywoodSapphire Group, SAE, IEEE and ASA.He has served the AES as chair of theLA Section; convention chair, papers

chair, chair of the Finance and Conven-tion Policy Committee; and a memberof the standards and technical commit-tees, and Review Board of the Journal.He has received the AES Board ofGovernors Award and a fellowship. Hewas previously president and vice pres-ident, Western Region, USA/Canada,and is currently serving his third termas treasurer. As treasurer he initiated aconservative investment program thathas returned significant appreciation,and streamlined the conference budgetprocess. He established and maintains amultiyear AES financial spreadsheetthat provides historical perspective andassists the management decision pro-cess for the Board of Governors.

VICE PRESIDENT,EASTERN REGION, USA/CANADA

JIM ANDERSON is a New York-based recordingengineer andproducer, spe-cializing in jazzand acoustic music. He hasrecorded pro-jects for artistssuch as ToshikoAkiyoshi, Patri-

cia Barber, Terence Blanchard, JamesCarter, Ron Carter, Jon Fadis, JoeHenderson, J. J. Johnson, LorinMaazel, Branford Marsalis, ChristianMcBride, Gonzalo Rubalcaba, MariaSchneider, McCoy Tyner, Phil Woods,and John Zorn, many of whom havereceived Grammy awards or nomina-tions. In television, he has worked withthe Muppets and as audio producer for“In Performance at the White House”for PBS, among others. Emmy awardnominations have been given to manyof his television projects.

A graduate of the Duquesne Univer-sity School of Music in Pittsburgh PA,he has studied audio engineering at theEastman School of Music and SenderFreies Berlin. During the 1970s, hewas employed by National Public Radio and engineered and producedmany award-winning classical, jazz,documentary, and news programs.Since 1980 he has had a career as anindependent audio engineer and pro-ducer, living in New York City. He

has given recording seminars for thetonmeister program of the HdK inBerlin and at the Berklee School ofMusic. During 1999 and 2000, he waschair of the New York Section and isnow chair emeritus.

VICE PRESIDENT, CENTRAL REGION, USA/CANADA

FRANK WELLS has been an AESmember forwell over adecade and isthe current chairof the NashvilleSection. He isalso a foundingboard memberof the nonprofitcorporation, the

Nashville Engineer Relief Fund,which aids area audio engineers intimes of crisis.

Wells is the editor of the profession-al audio news monthly, Pro SoundNews magazine, and executive editorof Surround Professional. He beganhis technical career as a USAF radiotechnician. In 1982, he received a B.S. degree (Summa Cum Laude) fromMiddle Tennessee State University inMass Communications Radio/-TV/Film. He worked for MTSU for sixyears as chief engineer of their 50 kWFM radio station, also working parttime as chief operator and technicianfor other area AM and FM stations.

Wells joined Glenn Meadows’ Mas-terfonics Studios in 1988 as chief oftechnical services. For nearly a decade,his responsibilities included all techni-cal aspects of the seven-room, two-building recording and mastering facil-ity. He also designed, built, andmaintained real-time cassette copy systems for Nashville labels and pub-lishing houses, and designed and implemented custom circuitry, modifi-cations and other solutions for variousstudios, engineers and recordingartists. Wells’ technical writing and industry experience led to his appoint-ment in 1997 as the founding editor ofAudio Media, USA. In 1999 he joinedPro Sound News/United EntertainmentMedia, also overseeing the AES Dailynewspaper for US conventions andhelping develop seminar programs


1074

such as the SPARS/UEM BizTechconference, Surround 2000 to 2002and AES workshops.

VICE PRESIDENT,WESTERN REGION, USA/CANADA

BOB MOSES is cofounder andchief technolo-gy officer ofDigital Harmo-ny Technolo-gies, a companywhich licensesn e t w o r k i n gtechnologies toprofessional au-dio, computer,

and consumer electronics OEMs. Pre-viously, Moses was a cofounder andvice president of PAVO, which pro-vided engineering services to Rane,Symetrix, JBL, Microsoft, Analog Devices, Altec Lansing Technologies,Harman, MIDI Manufacturers Associ-ation, Experience Music Project, andother companies before it was acquired in 2000.

Moses was senior digital audio engineer at Rane Corporation from1987 to 1996, and cofounded WadiaDigital Corporation in 1987. Currentlya member of the Board of Governors,Moses has been very active in the Audio Engineering Society since1987. He was program cochair of the13th International AES Conference in1994, and chair of the 18th Interna-tional AES Conference in 2001. Hehas chaired several AESSC subcom-mittees and working groups since1989, and was founding vice chair ofthe AES Technical Committee onNetwork Audio Systems in 1998.

Moses is currently co-vice chair ofAESSC SC-06-02 working group onProfessional Audio Applications ofIEEE 1394, and is the project teamleader of the IEC PT61883-6 Audioand Music Data Protocol Committee.He has served on the Steering Com-mittee of the Pacific Northwest AESSection since 1995.

Moses has published AES papersand chaired papers sessions and work-shops at many AES conventions,coauthored the book Digital Projectsfor Musicians with Craig Anderton,and written numerous articles for the

pro audio trade press. He was awardedthe IEEE Life Member Award in 1987.

VICE PRESIDENT,NORTHERN REGION, EUROPE

SØREN BECH received an M.Sc. in1982 and aPh.D. degree in1987, both fromthe Depart-ment of Acous-tic Technology(AT) of theTechnical Uni-versity of Den-m a r k . F r o m

1982 to 1992 he was a research fellowat AT, studying perception and evalu-ation of reproduced sound in smallrooms. In 1982 he joined Bang &Olufsen as technology specialist, responsible for the company’s research activities in human percep-tion of sound and picture.

In 2000 he was appointed adjunctprofessor at McGill University, Facultyof Music. Bech has done research in,and been project manager of, several international collaborative researchprojects including Archimedes (percep-tion of reproduced sound in smallrooms), ADTT (Advanced DigitalTelevision Technologies), Adonis (Im-age Quality of Television Displays),LoDist (perception of distortion inloudspeaker units), Medusa (multi-channel sound reproduction systems),and Vincent (flat panel display tech-nologies). He was cochair of the ITUtask group 10/3 and a member of taskgroup 10/4.

He was a member of the organizingcommittee and editor of a symposiumon “Perception of Reproduced Sound”in 1987, member of the Danish AESSection board (1986-88), section chair(1988-90), chair of the 12th AES Con-ference in 1992, member of the orga-nizing committee for the 100th AESConvention in 1996, papers cochairfor the 15th AES Conference in 1998,and AES governor (1996-1998). He ischair of the AES Conference PolicyCommittee, chair of the AES Techni-cal Committee on Perception andEvaluation of Audio Signals, and amember of the Review Board of theAES, ASA, and Acoustica Journals.

He is a fellow of the AES and ASA andhas published several papers in theJAES, JASA and other scientific journals.

VICE PRESIDENT, CENTRAL REGION, EUROPE

BOZENA KOSTEK received anM.Sc. degree insound engineer-ing (1983) andanother M.Sc. inorganization andm a n a g e m e n t(1986) from theGdansk Univer-sity of Technol-ogy, Poland. She

also received a Diplome d’Acoustique(1988) from the Paul Sabatier Universi-ty of Toulouse, France. In 1992, shesupported her Ph.D. degree at theGdansk University of Technology, andin 2000 her D.Sc. degree at the WarsawInstitute of Research Systems of thePolish Academy of Sciences. She is anassociate professor with the Sound andVision Engineering Department, GUT.Professor Kostek has presented morethan 200 scientific papers in journalsand international conferences, amongthem, 31 at Audio Engineering Soci-ety Conventions. In 1999, she pub-lished a book entitled Soft Computingin Acoustics.

In November 2000 she obtained anaward for scientific achievementsfrom the prime minister of Poland.She led a number of research projectssponsored by the Polish State Com-mittee for Scientific Research. In October 2002 “The Inventions in theDomain of Telemedical Hearing andSpeech Testing,” which she coau-thored, was awarded two Grand Prixprizes at the 51st “Brussels Eureka”World Exhibition. In 1991, she helpedform the Polish Section of the AudioEngineering Society and since thattime has served as a member of thecommittee. She was also a committeemember of the International Symposiaon Sound Engineering and Masteringheld every two years in Poland. Hermain scientific interests are studiotechnology, psychophysiology ofhearing, musical acoustics, as well asapplications of soft computing meth-ods to the above domains.


NEW OFFICERS

VICE PRESIDENT,SOUTHERN REGION, EUROPE

IVAN STAMAC was born inD u b r o v n i k ,Croatia. He hasbeen a memberof the AES since1974, an AESfellow since2000 and AESvice president,Southern Re-gion, Europe,

from 1997 to 2001. He was the key activist in founding the Croatian AESSection in 1993 and Croatian StudentSection in 1995, respectively.

Stamac received his B.S. degree inelectrical engineering from ZagrebUniversity in 1961. He then joinedRIZ Zagreb to design frequency syn-thesizers for radio transmitters. From1970 until 1996 he has been withCroatian Radio Television Zagreb incharge of room acoustics. He alsoworked as a tonmeister and taughtfunctional acoustics at the ZagrebUniversity’s Institute of Phonetics.Stamac educated audiophiles, leadinga 4-year broadcast series called “Small Lexicon of Good Sound.” Heis also a musician, plays piano andflute, but is at his best as a songwriter.He has won 21 prizes for his composi-tions. He is a member and former vicepresident of the Croatian Composers’Association, now serving on its Admissions Committee. Stamac alsoserved as the manager of the Zagrebfest Song Festival. His acousti-cal work comprises designs of morethan 60 performing and/or recordingsuites. For instance, the 54 record-ing/listening enclosures of the Croat-ian Radio and a recently built sound studio Red Light in Zagreb were built using Stamac’scompound acoustics building system.Stamac is an author or coauthor of 20papers on musical and room acousticsand holds four patents.

VICE PRESIDENT,INTERNATIONAL REGION

NEVILLE THIELE was educated atthe Universities of Queensland and

Sydney, gradu-ating with a B.E.degree (mechan-ical and electri-cal) in 1952. AtEMI (Australia)Ltd., he was involved in thedesign of tele-metry equipment

and domestic television receivers, and asadvanced development engineer, devised a method of measuring and designing loudspeakers. Further exten-sive work by Richard Small led to thesystem of loudspeaker design that has become known as the Thiele-Smallparameters. From 1962, at the Aus-tralian Broadcasting Corporation, heworked on the design and assessment ofradio and television equipment, and lateras director of engineering development.

Since 1985 he has been an indepen-dent consulting engineer and teachespart-time at the University of Sydney.He has been active for many years innational and international standards forbroadcasting, with Standards Aus-tralia, AES, IEC and ITU-R. He haspublished 37 papers on broadcastingsubjects and was awarded the SilverMedal by the AES for contributions toloudspeaker simulation and the Nor-man W.V. Hayes Award of the IREEAustralia, twice, for papers on televi-sion subjects. Thiele is a fellow of theAES and of the Institution of Engi-neers Australia (IE Aust.), and a mem-ber of the SMPTE. He was electedvice-president, International Region ofthe AES in 1992, and president of theInstitution of Radio and ElectronicsEngineers Australia (IREE) in 1987.

VICE PRESIDENT,LATIN AMERICA REGION

MERCEDES ONORATO was afounding mem-ber of the Ar-gentina Section,where she isnow the secre-tary. In 1990 shefounded her ownentrepreneurialcompany, pro-moting many

professional audio products. She


You can purchase thebook and CD-ROM online

at www.aes.org. For more informationemail Andy Veloz at

[email protected] telephone

+1 212 661 8528 x39.

THE PROCEEDINGSOF THE AES 22ND

INTERNATIONALCONFERENCE2002 June 15–17

Espoo, Finland

These 45 papers are devot-ed to virtual and augment-ed reality, sound synthesis,3-D audio technologies,audio coding techniques,physical modeling, subjec-tive and objective evalua-tion, and computationalauditory scene analysis.

believes that education is a vital part ofdeveloping a market and to this end hasorganized many educational events,inviting many international audio pro-fessionals to participate.

Onorato was a member of the 2000Latin America Grammy Awards Com-mittee. She has organized many semi-nars on behalf of the AES, attended bypeople from throughout Latin Ameri-ca. She was also very involved withElectroshow (an international Audio-Video Fair).

GOVERNORS

JERRY BRUCK was born in 1935 inSt. Louis, Mis-souri. Despite anearly interest inchemistry, py-rotechnics andradioactivity, hereached collegeage with onlyminor injuries. Aprudent shift of

interest to electronics and recordingtechnology, whetted by a consumingpassion for classical music, influencedhis early experimentation with binauralsound, while he was still attendingWashington University. After college hejoined St. Louis’s pioneering “good music” station as program director andstaff engineer. When Muzak replacedMahler at KCFM he moved to NewYork and joined the staff of WBAI in 1961.

In 1964 he decided to begin his free-lance recording career in earnest.With credits for LPs, film and videoprojects accumulating, Jerry joined theAES, and is now a life member. Hehas presented papers, participated inseminars and panels, and lectured inthe U.S. and Europe on minimalist microphone theory and practice. He introduced Mid-Side recording tech-nique to film and video soundtracks,and originated the KFM 360 Surroundmicrophone system. He has been chairof the AES New York Section severaltimes, was chair of the 91st Conven-tion, and has served as a governor ofthe Society. In 1999 he was given theAES Fellowship Award. For over aquarter century Bruck imported anddistributed Schoeps microphones in

the United States. His company,Posthorn Recordings, is now in its39th year as a dealer and distributor ofprofessional audio equipment. He remains active as a recording engineerand consultant for sundry music, filmand video projects.

RICHARD H. SMALL received aBachelor of Sci-ence degree fromthe CaliforniaInstitute of Tech-nology in 1956and a Master of Science de-gree in electricalengineering fromthe Massachu-

setts Institute of Technology in 1958.He was employed in electronic circuitdesign for high-performance analyticalinstruments at the Bell & Howell Research Center in California from1958 to 1964, except for a one-year vis-iting fellowship at the Norwegian Tech-nical University in 1961-62.

After a working visit to Japan in1964, he moved to Australia. In 1972,following the completion of a programof research into direct-radiator electro-dynamic loudspeaker systems, he wasawarded the degree of doctor of philos-ophy by the University of Sydney. Hethen joined the teaching staff of theSchool of Electrical Engineering of thatuniversity. In 1986 he resigned his position as senior lecturer to return to industry as head of research at KEFElectronics Limited in Maidstone,Kent.

In 1993 he returned to the UnitedStates where he currently holds theposition of senior principal engineerwith Harman/Becker Automotive Sys-tems in Martinsville, Indiana. Small isa senior member of the Institute ofElectrical and Electronics Engineersand a member of the Institution of Engineers Australia. He is a fellow ofthe Audio Engineering Society and a recipient of the Society’s PublicationAward (1976), Silver Medal (1982),and Gold Medal (1996). He has servedthe AES as a member of the Journal’sReview Board since 1973, as governor1989-1991, vice-chair of the Techni-cal Committee on Transducers 1992-1994, and chair of the PublicationsPolicy Committee since 1992.

PETER SWARTE began his career asa developer ofp r o f e s s i o n a l microphones andloudspeakers atPhilips Electron-ics in Eindhoven,the Netherlands,in 1964. He re-ceived a B.Sc.degree in physics

and developed several types of magne-to-dynamic, piezoelectric, electrody-namic and electret transducers for commercial, professional and securityapplications. In 1977 he began workingas an applications engineer for profes-sional audio systems. In this capacity heeducated and supported sales and pro-ject engineers worldwide within thePhilips Electronics organization in thedesign and realization of emergencysound systems, e.g. in sports stadiums,emporiums, airports, and congress cen-ters. He earned patents for active absorption and reflection systems and capacitive transducers. From 1987, asgroup manager, he gathered extensiveapplication knowledge about worldwidedata networks, videoconference systemsand digital audio communications. Heworked together with scientists for theapplication of an automatic interpreta-tion system where the phenomena ofspeech and intelligibility were of crucialimportance.

Since the beginning of 1998, he hasbeen an independent consultant foracoustics and electroacoustics. Togetherwith scientists at the research lab atPhilips Electronics he developed the“dormant Base” (“dB”) equipment forthe elimination of annoying sound emit-ted, for example, into sleeping rooms,by discotheques and entertainment cen-ters. Swarte teaches a postgraduatecourse in electroacoustics in Belgium.He is vice chair of the Netherlands Sec-tion. In 2000 he was chair for the 110thAES Convention, and he occupied thischair again in 2003 for the 114th AESConvention, both in Amsterdam.


The preceding biographies were pro-vided by the respective officers.While the Audio Engineering Societybelieves them to be accurate, it cannot assume responsibility for accuracy or completeness.


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Faculty AdvisorBill SmithAES Student SectionFull Sail Real World Education3300 University Blvd., Suite 160 Winter Park, FL 32793Tel. +1 800 679 0100E-mail [email protected]

…University of Miami Section (Student)

Chair:James Buchanan9894 SW 88st # c-112Mimi, FL 33176Tel. +1 786 514 5027 E-mail [email protected]

Vice Chair:Becky Stewart

Secretary:Ed Etayo

Treasurer:Marc Beitchman

Faculty Advisor:Ken PohlmannAES Student SectionUniversity of MiamiSchool of MusicCoral Gables, FL 33124-7610Tel. +1 305 284 6252Fax +1 305 284 4448E-mail [email protected]

Mailing Address: AES Student Sectionc/o Ken PohlmannUniversity of MiamiSchool of MusicCoral Gables, FL 33124-7610

GEORGIA

Atlanta Section

Chair:James YearyTurner StudiosEngineering Audio Team1020 Techwood Drive N.W.Atlanta, GA 30318Tel. +1 404 885 4605Fax +1 404 878 4023E-mail [email protected]

[email protected]

Vice Chair:Joe TymeckiTurner Studios1050 Techwood Drive N.W.Atlanta, GA 30318Tel. +1 404 885 2023Fax +1 404 885 4485E-mail [email protected]

Secretary:Robert Mason2712 Leslie DriveAtlanta, GA 30345Tel./Fax +1 770 908 1833E-mail [email protected]

Treasurer:Leslie Jensen-Link6151 Powers Ferry Road, Ste. 230Atlanta, GA 30303Tel. +1 770 818 9180Fax +1 770 818 9179E-mail [email protected]

Committee:Jeff BruggerGary OsteenPeter Young

MARYLAND

Peabody Institute of Johns HopkinsUniversity Section (Student)Chair:Tyrone HunterTel. +1 410 727 3139 ext. 1276E-mail [email protected]

Vice Chair:Ryan Simms

EASTERN REGION, USA/CANADA

2004/2005 AES INTERNATIONAL SECTIONS DIRECTORYThe following information was received from the sections by press time. If additional information or corrections tothese listings are necessary, please forward the pertinent details and they will be published in a forthcoming update.Several sections maintain their own Web pages and links to these can be found on the AES Web site athttp://www.aes.org under the heading “sections.”

Tel. +1 410 468 0387E-mail [email protected]

Secretary:Rob LewisTel. +1 410 669 4954E-mail [email protected]

Treasurer:Melissa BethelTel. +1 443 622 5283E-mail [email protected]

All correspondence to

Faculty Advisor:Neil ShadeAES Student SectionPeabody Institute of Johns Hopkins

UniversityRecording Arts & Science Department2nd Floor Conservatory Building, Rm. 2161 East Mount Vernon PlaceBaltimore, MD 21202Tel. +1 410 659 8100 ext. 1226E-mail [email protected]

MASSACHUSETTS

Berklee College of Music Section(Student)

Faculty Advisor:Eric ReuterBerklee College of MusicAudio Engineering Societyc/o Student Activities1140 Boylston Street Box #82Boston, MA 02215Tel. +1 617 747 8251Fax +1 617 747 2179E-mail [email protected]

…Boston Section

Chair:Jordan TishlerDigital Bear EntertainmentP.O. Box 1142Boston, MA 02130-0010Tel. +1 617 522 4550Fax +1 617 983 8332E-mail [email protected]

Vice Chair:Eric Reuter1416 South RoadRye, NH 03870Tel. +1 603 964 6383E-mail [email protected]

Secretary:J. Nelson Chadderdonc/o Oceanwave Consulting, Inc.21 Old Town RoadBeverly, MA 01915Tel. +1 978 232 9535 x201Fax +1 978 2329537E-mail [email protected]

Treasurer:Joel M. Goldberg

IET Labs, CPL Operation728 Dedham StreetNewton Centre, MA 02459-2937Tel. +1 617 964 7224E-mail [email protected]

Executive Committee:Alex CaseMatt GirardIra LeonardJ. Spencer LoveMatthew MooreDavid MoultonMark ParsonsDon PuluseDan RoseJeff RossenbergTom Wethern

…University of Massachusetts–LowellSection (Student)

Chair:Aaron Krasnick

Vice Chair:Mark HendersonTel. +1 978 618 1781E-mail [email protected]

Secretary:Richard Kwan

Treasurer:Greg Maloney


Faculty Advisor:John ShirleyAES Student ChapterUniversity of Massachusetts–LowellDepartment of Music35 Wilder Street, Suite 3Lowell, MA 01854-3083Tel. +1 978 934 3886Fax +1 978 934 3034E-mail [email protected]

…Worcester Polytechnic Institute Section(Student)

Faculty Advisor:William MichalsonAES Student SectionWorcester Polytechnic Institute100 Institute RoadWorcester, MA 01609Tel. +1 508 831 5766E-mail [email protected]

NEW JERSEY

William Paterson University Section(Student)

Chair: Vince VerderameTel. +1 856 419 4368E-mail [email protected]

Vice Chair: Sam MacyTel. +1 201 891 9194E-mail [email protected]

Secretary:Dave WillardTel. +1 973 263 3091E-mail [email protected]

Treasurer:Tito D. VallejoTel. +1 973 773 6335E-mail [email protected]


Faculty Advisor:David KerznerAES Student SectionWilliam Paterson University300 Pompton RoadWayne, NJ 07470-2103Tel. +1 973 720 3198Fax +1 973 720 2217E-mail [email protected]

NEW YORK

Fredonia Section (Student)

Chair: Nate StengrevicsTel. +1 716 672 6624E-mail [email protected]

Vice Chair:Ben WitteTel. +1 716 679 0395E-mail [email protected]

Secretary:Todd MazierskiTel. +1 716 673 4011E-mail [email protected]

Treasurer:Jeremy RoseTel. +1 716 679 1198E-mail [email protected]

Faculty Advisor (Section Contact):Bernd GottingerAES Student SectionSUNY–Fredonia1146 Mason HallFredonia, NY 14063Tel. +1 716 673 4634 Fax +1 716 673 3154 E-mail [email protected] Office:Tel. +1 716 679 3165

…Institute of Audio Research Section(Student)

Faculty Advisor:Noel SmithAES Student SectionInstitute of Audio Research64 University PlaceNew York, NY 10003


INTERNATIONAL SECTIONS DIRECTORY

Tel. +1 212 677 7580Fax +1 212 677 6549E-mail [email protected]

...NEW YORK SECTION

Chair:Allan TuckerFoothill Digital Productions215 West 91st StreetNew York, NY 10024Tel. +1 212 877 0973E-mail [email protected]

Vice Chair:Elliot MazerTel. +1 917 302 1989E-mail [email protected]

Secretary:Bill SiegmundDigital Island Studios71 West 23rd Street Suite 504New York, NY 10010Tel. +1 212 243 9753E-mail [email protected]

Treasurer:Tim CaseyStudio Consultants321 West 44th StreetNew York, NY 10036Tel. +1 212 586 7376E-mail [email protected]

Committee:Robert AuldDavid BakerDavid BialikDan GaydosKen HunoldDavid PrenticeAlan SilvermanKatharina Tapp

Advisors:Ron AjemianJim AndersonJerry BruckAlbert B. GrundyIrv Joel

NORTH CAROLINA

University of North Carolina atAsheville (Student)

Chair:Emily Ellis

Vice Chair:Lindsey Kari

Secretary:Justin Baumann

Treasurer:John Inglese

Faculty Advisor:Wayne J. Kirby

AES Student SectionUniversity of North Carolina at AshevilleDepartment of MusicOne University HeightsAsheville, NC 28804Tel. +1 828 251 6487Fax +1 828 253 4573E-mail [email protected]

PENNSYLVANIA

Carnegie Mellon University Section(Student)

Chair:Mark DambacherTel. +1 412 268 4002Fax +1 412 268 5576E-mail [email protected]

Vice Chair:Timothy WarneckTel. +1 412 688 0244E-mail [email protected]

Secretary:Naomi DambacherTel. +1 412 268 4002E-mail [email protected]

Treasurer:Mike BeuselinkTel. +1 412 421 7931E-mail [email protected]

Faculty Advisors:Riccardo Schulz (Music)Thomas Sullivan (ECE)Ned VanDerven (Physics)


Faculty Advisor:Thomas SullivanAES Student SectionCarnegie Mellon UniversityUniversity Center Box 122Pittsburg, PA 15213Tel. +1 412 268 3351E-mail [email protected]

…Duquesne University Section (Student)

Chair:Matt MorelliTel. +1 412 745 2122E-mail [email protected]

Vice Chair:Carl CostickTel. +1 412 481 4620E-mail [email protected]

Secretary:Chris LokenTel. +1 412 396 7739E-mail [email protected]

Treasurer:Lewis TozourTel. +1 412 803 3323E-mail [email protected]


Faculty Advisor:Francisco RodriguezAES Student SectionDuquesne UniversitySchool of Music600 Forbes AvenuePittsburgh, PA 15282Tel. +1 412 434 1630Fax +1 412 396 5479E-mail [email protected]

Co-advisor:Thomas HaasMary Pappert School of MusicDuquesne University600 Forbes AvenuePittsburgh, PA 15282Tel. +1 412 396 1695Fax +1 412 396 5479E-mail [email protected]

…Pennsylvania State University Section(Student)

Chair (Section Contact):Dan ValenteTel. +1 814 865 2859E-mail penn–[email protected]

Vice Chair:Alexandra LoubeauTel. +1 814 865 2859E-mail [email protected]

Secretary:Ben DotyTel. +1 814 865 2859E-mail [email protected]

Treasurer:Mark GramannTel. + 814 863 5695E-mail [email protected]

Faculty Advisors:Steven GarrettJiri Tichy

Committee:Rachel RomondMark Wochner

Mailing Address:AES Penn State Student ChapterGraduate Program in Acoustics217 Applied Science BuildingUniversity Park, PA 16802Fax +1 814 865 3119

…Philadelphia Section

Chair:Bill GellhausWMRG Studios Inc.P.O. Box 73Cheltenham, PA 19012Tel. +1 215 635 4815Fax +1 215 782 8090E-mail [email protected]

Vice Chair:John Uhl


P.O. Box 66Annville, PA 17003Tel. +1 717 867 2669E-mail [email protected]

Secretary:Rebecca MercuriP.O. Box 1166Philadelphia, PA 19105Tel. +1 609 895 1375E-mail [email protected]

Treasurer:Warren R. WilsonForge Recording Studios, Inc.P.O. Box 861Valley Forge, PA 19481Tel./Fax +1 610 935 0121E-mail [email protected]

Member at Large:Bob Collom7428 Devon StreetPhiladelphia, PA 19119Tel. +1 215 247 9416

VIRGINIA

Hampton University Section (Student)

Chair:Nefertari Kirkman-BeyTel. +1 757 218 6886E-mail [email protected]

Vice Chair:Dell HarrisTel. +1 757 723 4374E-mail [email protected]

Secretary:Miguel BrownTel. +1 804 720 0609E-mail [email protected]

Treasurer:Lavonya KnightTel. +1 757 728 4185E-mail [email protected]


Faculty Advisor:Bob RansomAES Student SectionHampton UniversityDepartment of MusicHampton, VA 23668Tel. +1 757 727 5658, +1 757 727 5404Home Tel. +1 757 826 0092Fax +1 757 727 5084E-mail [email protected]

WASHINGTON, DC

American University Section (Student)

Chair:Kelly Reidy

Vice Chair:Jeff McAleer

Secretary:Kristof Aldenderfer

Treasurer:Dan Melewski

Faculty Advisor:Mark SariskyAES Student SectionAmerican UniversityPhysics Department4400 Massachusetts Avenue, N.W.Washington, DC 20016Tel. +1 202 885 2746Fax +1 202 885 2723E-mail [email protected]

…District of Columbia Section

Acting Chair:Richard Cassidy Cassidy & Associates1928 Dundee RoadRockville, MD 20850-3137Tel. +1 202 885 1236E-mail [email protected]

Vice Chair:John Kean3219 Potterton DriveChurch Falls, VA 22044Home Tel. +1 703 532 8630Office Tel. +1 703 741 3560E-mail [email protected]


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Prism Media Products LimitedWilliam James House,Cowley Road, Cambridge. CB4 0WX. UK.

Tel: +44 (0)1223 424988Fax: +44 (0)1223 425023

[email protected]

Prism Media Products Inc.21 Pine Street, Rockaway, NJ. 07866. USA.

Tel: 1-973 983 9577 Fax: 1-973 983 9588

www.prismsound.com

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Secretary:John W. ReiserP.O. Box 169Mt. Vernon, VA 22121-0169Tel. +1 703 780 4824Fax +1 703 780 4214E-mail [email protected]

Treasurer:Richard CassidyCassidy & Associates1928 Dundee RoadRockville, MD 20850Tel. +1 202 885 1236E-mail [email protected]

Committee:Gary GibianKim Haug

CANADAMcGill University Section (Student)

Chair:Brad AndrewsTel. +1 514 398 4549E-mail [email protected]

Secretary:Anne-Marie SylvestreTel. +1 514 398 4549E-mail [email protected]

Treasurer:Nathan PicklykTel. +1 514 398 4549E-mail [email protected]

Faculty Advisor:John KlepkoTel. +1 514 398 4535 ext. 0454E-mail [email protected]

Mailing Address:AES Student SectionMcGill UniversitySound Recording StudiosStrathcona Music Building555 Sherbrooke Street WestMontreal, Quebec H3A 1E3, Canada

…Toronto Section

Chair:Jim Cox235 Douglas AvenueOakville, OntarioL6J 3S2, CanadaTel. +1 905 845 4620E-Mail [email protected]

Vice Chair:Garrick Filewod225 Douglas AvenueToronto, Ontario, CanadaTel. +1 416 979 5000 ext. 6872E-mail [email protected]

Contact Secretary/Bulletin Publisher:Anne ReynoldsDeluxe Laboratories

606-50 Casburn AvenueToronto, Ontario M4K 2G5, CanadaTel. +1 416 957 6204Fax +1 416 364 1310E-mail [email protected]

Treasurer:Paul Reibling30-219 Kingswood DriveKitchener, Ontario N2E 3J5, CanadaTel. +1 519 745 1158 ext. 243Fax +1 519 745 2364E-mail [email protected]

Committee:Peter CookJames HaywoodDoug McClementDan MombourquetteGlenn SpechtRob Stevens

Vice President:Jim KaiserMaster Mix1921 Division StreetNashville, TN 37203Tel. +1 615 321 5970Fax +1 615 321 0764E-mail [email protected]


ARKANSAS

University of Arkansas at Pine Bluff(Student)

Faculty Advisor:Robert ElliottMusic Department, University of Arkansas

at Pine Bluff1200 North University DrivePine Bluff, AR 71601Tel. +1 870 575 8916Fax +1 870 543 8108E-mail [email protected]

INDIANA

Ball State University Section (Student)

Chair:Josh ArnoldTel. +1 765 287 0713E-mail [email protected]

Vice Chair:Sarah SknerskiTel. +1 765 214 2019E-mail [email protected]

Secretary:Jay RyanTel. +1 765 214 3101E-mail [email protected]

Treasurer:Derek EdwardsTel. +1 765 214 9061E-mail [email protected]


Faculty Advisor:Michael PoundsBall State UniversityMET Studios2520 West BethelMuncie, IN 47306Tel. +1 765 285 5537Fax +1 765 285 8768E-mail [email protected]

…Central Indiana Section

Chair:Jeff D. SzymanskiAuralex Acoustics8851 North Hague RoadIndianapolis, IN 46256Office Tel. +1 317 842 2600Fax +1 317 842 2760E-mail [email protected]

Vice Chair:Barrie L. Zimmerman311 West Sample RoadBloomington, IN 47404Office Tel. +1 812 855 2898Fax +1 812 855 0729E-mail [email protected]

Secretary:James LattaSound Around6349 Warren LaneBrownsburg, IN 46112Office Tel. +1 317 852 8379Fax +1 317 858 8105E-mail [email protected]

Treasurer:John W. LyzottZott Engineering2531 Webb StreetIndianapolis, IN 46225Office Tel. +1 317 784 3438Fax +1 317 784 2567E-mail [email protected]

Committee:Mark FritzPeter ScheiberJeff SeitzM. David Wright

ILLINOIS

Chicago Section

Chair:A. J. BautistaE-mail [email protected]

Vice Chair:Bob ZurekE-mail [email protected]

Secretary:Tom MillerKnowles Electronics1151 Maplewood Dr.Itasca, IL 60143Tel. +1 630 285 5882

CENTRAL REGION, USA/CANADA


Fax +1 630 250 0575E-mail [email protected]

Treasurer:Simone KooMotorola 2001 North Division Street, MS AN284Harvard, IL 60033Tel. +1 815 884 2133Fax +1 815 884 2519E-mail [email protected]

Committee:Jim BrownTom MillerDave PrinceMarty ReilingBob SchuleinJeff SegotaRon Steinburg

…Columbia College Section (Student)

Chair:Tom GundersonTel. +1 708 757 6946E-mail [email protected]

Vice Chair: Melvin SaundersTel. +1 708 481 7151E-mail [email protected]

Treasurer: Andrew GortonTel. +1 773 989 4729E-mail [email protected]

Committee:Andy Pollina


Faculty Advisor:Dominique J. ChéenneAES Student Section676 North LaSalle, Suite 300

Chicago, IL 60610Tel. +1 312 344 7802Fax +1 312 482 9083E-mail [email protected]

…University of Illinois at Urbana-

Champaign (Student)

Chair/Contact:David S. Petruncio Jr.University of Illinois, Urbana-ChampaignUrbana, IL 61801Tel. +1 217 621 7586E-mail [email protected]

Vice Chair:Brian SheinTel. +1 217 766 7606E-mail [email protected]

Secretary:Jeff ZahosTel. +1 217 328 7545E-mail [email protected]

Treasurer:Zion ParkTel. +1 217 721 8282E-mail [email protected]

Faculty Advisor:Mark Hasegawa-JohnsonUniversity of Illinois, Urbana-ChampaignUrbana, IL 61801Tel. +1 217 333 0925E-mail [email protected]

Public Relations Director:Chris WaltiTel. +1 217 344 4094E-mail [email protected]

Webmaster:John HorstmanTel. +1 217 721 7121E-mail [email protected]

Career/Apprenticeship Director:Eric BellasTel. +1 217 344 8524E-mail [email protected]

KANSAS

Kansas City Section

Chair:Michael S. TremainTremain Marketing Group3725 BroadwayKansas City, MO 64111Tel. +1 816 931 9664Fax +1 816 931 4456

Vice Chair:David BartlettEntertainment Technology1914 Heriford RoadColumbia, MO 65202Tel. +1 314 474 6788

Secretary:Jim MitchellCustom Distribution Limited12301 Riggs RoadOverland Park, KS 66209Tel. +1 913 661 0131Fax +1 913 663 5662

Treasurer:Bob HayworthRLDS Electronic Communications1001 West Walnut StreetIndependence, MO 64051Tel. +1 816 833 1000, ext. 1436

Committee:Dave DugdalePaul GordockiBob Pruit

LOUISIANA

New Orleans Section



Chair:Jay Gallagher400 Lafayette St.New Orleans, LA 70130Tel. +1 504 899 0082E-mail [email protected]

Vice Chair:David Farrell7210 Washington Ave.New Orleans, LA 70128Tel. +1 504 486 4873Fax +1 504 488 1057E-mail [email protected]

Secretary:Joe DohertyFactory Masters6411 <agazome St/New Orleans, LA 70115Tel. +1 504 891 4424Cell +1 504 669 4571Fax +1 504 899 9262E-mail [email protected]

Treasurer:Carr WilkersonE-mail [email protected]

MICHIGAN

Detroit Section

Chair (and Contact):David CarlstromP.O. Box 721464Berkley, MI 48072-0464Office Tel. +1 313 493 4035Home Tel. +1 248 544 8453Fax +1 313 653 5256E-mail [email protected]

Vice Chair:Earl GeddesGedLee Associates43516 Scenic LaneNorthville, MI 48167Tel. +1 248 305 9328Fax +1 248 305 9320E-mail [email protected]

Secretary:Tom ConlinDaimlerChryslerE-mail [email protected]

Treasurer:Robert KlaczaDaimlerChryslerTel. +1 313 493 3032Fax +1 313 493 4448E-mail [email protected]

Committee:David ClarkJohn MalekBernhard MullerLou Pagnucco

…Michigan Technological UniversitySection (Student)Chair (Section Contact):Greg Piper

1011 4th StreetHancock, MI 49930E-mail [email protected] [email protected]

Vice Chair:Mike Kasten701 W. South St.Houghton, MI 49931Tel. +1 906 482 0713E-mail [email protected]

Secretary:Chris Rokke425 EWH/1701 Townsend DriveHoughton, MI 49931Tel. +1 906 483 7283E-mail [email protected]

Treasurer:Brian Bresnahan431 Scott St. Apt. 2Hancock, MI 49930Tel. +1 906 483 3592E-mail [email protected]

Faculty Advisor:Andre LaRoucheAES Student SectionMichigan Technological UniversityElectrical Engineering Dept.1400 Townsend Dr.Houghton, MI 49931Home Tel. +1 906 847 9324

…West Michigan SectionChair:John Loser16 Shellenberger AvenueBattle Creek, MI 49017Tel. +1 616 528 9850Fax +1 616 538 4311E-mail [email protected]

Vice Chair:Max Krueger442 East Franklin StreetOtsego, MI 49078Tel. 616-844-1662Fax 616-855-1582E-mail [email protected]

Secretary:Carl HordykCalvin College3201 Burton S.E.Grand Rapids, MI 49546Tel. +1 616 957 6279Fax +1 616 957 6469E-mail [email protected]

Treasurer:Mark SayerMeniscus Audio3275 Gladiola AvenueWyoming, MI 49509Tel. +1 616 534 9121Fax +1 616 534 7676E-mail [email protected]

Committee:Kevin BlairTim Kleis Jim Welsh Tom Yackish

MINNESOTA

Music Tech College Section (Student)

Chair:Benjamin C. MelbyE-mail [email protected]

Vice Chair:Joe WolfeE-mail [email protected]

Secretary:Daryll HurstE-mail [email protected]

Treasurer:Mike MarstonE-mail [email protected]

Faculty Advisor:Michael McKernAES Student SectionMusic Tech College19 Exchange Street EastSaint Paul, MN 55101Tel. +1 612 338 0175Fax +1 612 338 0804E-mail [email protected]

…Ridgewater College, HutchinsonCampus Section (Student)

Chair:Chris BlaisTel. +1 320 234 3661E-mail [email protected]

Vice Chair/Secretary:Mike LudoweseTel. +1 320 562 2176E-mail [email protected]

Treasurer:Ezra NormanTel. +1 218 831 7562

Faculty Advisor:Dave IglE-mail [email protected]

Committee:Barry KratzkeDon LarsonBrad Van Vorst

Mailing Address:AES Student SectionRidgewater College, Hutchinson Campus2 Century Avenue S.E.Hutchinson, MN 55350

…Upper Midwest Section

Chair/Contact:Phil MendelsohnE-mail [email protected]

Secretary:Greg ReiersonRare Form Mastering4624 34th Avenue SouthMinneapolis, MN 55406


Tel. +1 612 327 8750E-mail [email protected]

Treasurer:Jason SpartzSaint Mary’s University of Minnesota700 Terrace Heights, #17Winona, MN 55987Tel. +1 507 457 1641Fax +1 507 457 1633E-mail [email protected]

Committee:Larry GlennDavid IglBruce OlsonPreston Smith

MISSOURI

St. Louis Section

Chair:John Nolan, Jr.693 Green Forest DriveFenton, MO 63026Tel./Fax +1 636 343 4765E-mail [email protected]

Vice Chair:Gary Koester3036 Shelley Lynn DriveArnold, MO 63010

Treasurer:William F. Carver2515 South Big Bend Blvd.St. Louis, MO 63143Tel. +1 314 965 9005

NEBRASKA

Northeast Community College Section(Student)

Chair:Gabe Stoakes

Vice Chair:Jefferson Roberts

Secretary:Ryan Richards

Treasurer:Josh Simonson


Faculty Advisor:Anthony D. BeardsleeAES Student SectionNortheast Community CollegeP.O. Box 469Norfolk, NE 68702Tel. +1 402 844 7365Fax +1 209 254 8282E-mail [email protected]

OHIO

Ohio University Section (Student)

Chair:Adam McCreaTel. +1 740 589 4363E-mail [email protected]

Vice Chairs:Neil OkonakTel. +1 740 597 7294E-mail [email protected]

B. Mackenzie SmithTel. +1 740 593 5180E-mail [email protected]

Secretary (Section Contact):Erin M. DawesTel. +1 740 597 6608E-mail [email protected]

Treasurer:Erin WillisTel. +1 740 597 9407E-mail [email protected]

Web Master:Matt Hyclak

Faculty Advisor:Jeff RedeferMailing Address:AES Student SectionOhio UniversityRTVC Building9 South College StreetAthens, OH 45701-2979E-mail [email protected]

…University of Cincinnati Section(Student)

Chair: Brad SchnittgerTel. +1 513 621 5179E-mail [email protected]

Vice Chair: Dan LudwigTel. +1 513 381 5065E-mail [email protected]

Secretary: Mike SheidlerE-mail [email protected]

Treasurer: Mike IngramE-mail [email protected]

Co-captain:Jason SebastianTel. +1 513 269 4915

Web Master:Brian Niesz

Committee:Brian NieszJason Sebastian


Faculty Advisor:Thomas A. HainesAES Student SectionUniversity of CincinnatiCollege-Conservatory of MusicM.L. 0003Cincinnati, OH 45221

Tel. +1 513 556 9497Fax +1 513 556 0202E-mail [email protected]

TENNESSEE

Belmont University Section (Student)

Chair:Jeff Comas

Vice Chair:Lisa Roberson

Secretary:Letretha Yount

Treasurer:Rob Huffstedtler

Committee:Doug Sadtler


Faculty Advisor:Wesley BullaAES Student SectionBelmont UniversityNashville, TN 37212E-mail [email protected]

…Middle Tennessee State UniversitySection (Student)

Chair:Courtney BloodingE-mail [email protected]

Chair Elect/Membership Coordinator:Aaron SeftonTel. +1 615 849 8113E-mail [email protected]

Secretary:Norman TealeE-mail [email protected]

Treasurer:Ryan KyzarE-mail [email protected]

Webmaster:Tommy ByrdE-mail [email protected]

Faculty Advisor:Doug MitchellAES Student SectionMiddle Tennessee State University301 East Main Street, Box 21Murfreesboro, TN 37132Tel. +1 615 898 2553E-mail [email protected]

Committee:Dan Ervin

…Nashville Section

Chair:Frank Wells



Pro Sound NewsP. O. Box 10564Murfreesboro, TN 37129Office Tel. +1 615 848 1769OfficeFax +1 615 848 1108E-mail [email protected]

Vice Chair:Mike Poston Equipment Pool478 Craighead Street, Suite 107Nashville, TN 37204Office Tel. +1 615 298 3270Fax +1 615 385 3145E-mail [email protected]

Secretary:Tom EdwardsMTV Networks330 Commerce StreetNashville, TN 37201Office Tel. +1 615 335 8520Fax +1 615 335 8608E-mail [email protected]

Treasurer:Steve Goostree LifeWay Christian ResourcesOne Lifeway PlazaNashville, TN 37234Office Tel. +1 615 251 2295E-mail [email protected]

Committee:Wesley BullaMichael DavisLynn FustonDavid HensonJohn JaszczJim KaiserKerry KoppTracy MartinsonDoug MitchellGary OldenbroekRandy PooleSEVAEd SimontonDavid StreitBil VornDick

...

SAE Nashville Section (Student)

Faculty Advisor:Mark MartinAES Student Section7 Music Circle NorthNashville, TN 37203Tel. +1 615 244 5848Fax +1 615 244 3192E-mail [email protected]

TEXAS

Southwest Texas State UniversitySection (Student)

Chair:Doug Prater Tel. +1 281 827 5526E-mail [email protected]

Vice Chair:Debra Ward Tel. +1 210 663 7873E-mail [email protected]

Secretary:Christopher JensenTel. +1 210 355 1051E-mail [email protected]

Treasurer:Stephen WorleyTel. +1 512 353 2131E-mail [email protected]


Faculty Advisor:Mark Erickson AES Student SectionSouthwest Texas State University224 North Guadalupe StreetSan Marcos, TX 78666Tel. +1 512 245 8451Fax +1 512 396 1169E-mail [email protected]

Vice President:Bob MosesIsland Digital Media Group, LLC26510 Vashon Highway S.W.Vashon, WA 98070Tel. +1 206 463 6667Fax +1 810 454 5349E-mail [email protected]


ARIZONA

Conservatory of The Recording Artsand Sciences Section (Student)

Chair (and Contact):Shane Matsumoto

Vice Chair:Erica HolmstromE-mail [email protected]

Secretary:Spence Kiddle

Treasurer:Chris Elly

Faculty Advisor:Glenn O’Hara AES Student Section Conservatory of The Recording Arts

and Sciences2300 East Broadway RoadTempe, AZ 85282Tel. +1 480 858 9400, 800 562 6383 Fax +1 480 829 1332E-mail [email protected]

CALIFORNIA

American River College Section(Student)

Chair:Felice Santos-Martin8139 Sunset Ave. #141Fair Oaks, CA 95628Tel. +1 916 802 2084E-mail [email protected]

Vice Chair:Katie Turner7007 Woodrick WaySacramento, Ca 95842Tel. +1 916 338 0917E-mail [email protected]

Secretary/Treasurer:Michael LaneE-mail [email protected]

Members at Large:Robert HightowerRandy KizerEric SimmsGlenn TietjenFaculty Advisor:Eric ChunAES Student SectionAmerican River College Chapter4700 College Oak DriveSacramento, CA 95841Tel. +1 916 484 8420E-mail [email protected]

...Cal Poly San Luis Obispo StateUniversity Section (Student)Chair:Adrian RolufsTel. +1 805 546 0996E-mail [email protected]

Vice Chair:Eric AmendtTel. +1 805 215 8206E-mail [email protected]

Secretary:Steven JeuckTel. +1 805 547 1778E-mail [email protected]

Treasurer:Bridger T. WrayTel. +1 805 593 0662E-mail [email protected]

Committee:Eric EamendtAdrian Rolufs

Faculty Advisor:Jerome R. BreitenbachAES Student SectionCalifornia Polytechnic State UniversityDepartment of Electrical EngineeringSan Luis Obispo, CA 93407Tel. +1 805 756 5710Fax +1 805 756 1458E-mail [email protected]

...California State University–ChicoSection (Student)

WESTERN REGION, USA/CANADA


Chair: Joel Bernstein

Vice Chair:Matt Fidler

Secretary:Dan Faustine

Treasurer:Glenn Maxon

Communications:Steve Barber


Faculty Advisor:Keith SeppanenAES Student SectionCalifornia State University–Chico400 West 1st StreetChico, CA 95929-0805Tel. +1 530 898 5500E-mail [email protected]

…Citrus College Section (Student)

Chair:Karen Romo

Vice Chair:Eric Balane

Secretary:Tanya Ghanime

Treasurer:David Hood

Faculty Advisor:Stephen O’HaraAES Student SectionCitrus CollegeRecording Arts1000 West Foothill Blvd.Glendora, CA 91741-1899Fax +1 626 852 8063

…

Cogswell Polytechnical College Section(Student)

Chair: Mitchell BaptistE-mail [email protected]

Co-chair:Stanley FincherE-mail [email protected]

Secretary:Barrett ClarkE-mail [email protected]

Treasurer:Charles RiceE-mail [email protected]

Faculty Sponsor:Tim DuncanAES Student SectionCogswell Polytechnical CollegeMusic Engineering Technology1175 Bordeaux DriveSunnyvale, CA 94089Tel. +1 408 541 0100, ext. 130Fax +1 408 747 0764E-mail [email protected]

…Expression Center for New MediaSection (Student)

Chair:Drake GeramoniHome Tel. +1 925 875 1836School Tel. +1 510 6542934E-mail [email protected]

Vice Chair:Yonatan ElkayamHome Tel. +1 510 644 8326E-mail [email protected]

Treasurer:Peter HardingHome Tel. +1 510 849 0470E-mail [email protected]

Faculty Advisor:Scott TheakstonAES Student SectionExpression Center for New Media6601 Shellmount StreetEmeryville, CA 94608Tel. +1 510 654 2934Fax +1 510 658 3414E-mail [email protected]

…

Long Beach City College Section(Student)


Faculty Advisor:Nancy AllenAES Student SectionLong Beach City College4901 East Carson StreetLong Beach, CA 90808Tel. +1 562 938 4312Fax +1 562 938 4409E-mail [email protected]

…Los Angeles Section

Chair:Ted Leamy8500 Balboa Blvd.Northridge, CA 91329Office Tel. +1 818 830 8771Home Tel. +1 818 878 1515E-mail [email protected]

Vice Chair:Richard L. Hess

National Teleconsultants, Inc.700 North Brand Blvd., 10th FloorGlendale, CA 91203-1202Tel. +1 818 265 4400Fax +1 818 265 4455E-mail [email protected]

Secretary:Andrew Turner1733 Lucile Avenue, #8Los Angeles, CA 90026Tel. +1 323 661 0390E-mail [email protected]

Treasurer:Kahne KrauseP.O. Box 3381Glendale, CA 91221Tel. +1 818 544 3622E-mail [email protected]

Newsletter Editor:Bob Lee

Committee:George BinerEthan R. BushKelli ClarkMel LambertBob LeeChris PalmerTim ShuttleworthSteven J. Venezia

…San Diego Section

Chair:Josef Kucera1535 Madrid Drive Vista, CA 92083Tel. +1 858 534 8868Fax +1 858 534 7685E-mail [email protected]

Vice Chair:Dave ReedMoonlight Sound/Stonebridge MusicP.O. Box 230481 Encinitas, CA 92023-0481Tel. +1 760 942 9540Fax +1 760 942 6787E-mail [email protected]

Secretary:J. Russell Lemon2031 Ladera CourtCarlsbad, CA 92009-8521Home Tel. +1 760 753 2949E-mail [email protected]

Treasurer:Tim Cuthbertson29511 Hoxie Ranch RoadVista, CA 92084Tel. +1 760 940 4196Fax +1 760 940 4156E-mail [email protected]

Program Committee: Vance Breshears



Trever HenthornPeter OttoRoni Sue Player Vladimir Vooss

Education Committee:Brian Cantarini John Hildebrand Josef KuceraJim Papageorge

…

San Diego State University Section(Student)

Chair:Kent PingreyTel. +1 619 279 7692E-mail [email protected]

Vice Chair:Trenton BlizzardTel. +1 619 462 5121E-mail [email protected]

Secretary:Jimmy D. MooreTel. +1 619 561 5644E-mail [email protected]:Ray SalemTel. +1 619 463 1478


Faculty Advisor:John KennedyAES Student SectionSan Diego State UniversityElectrical & Computer

Engineering Department5500 Campanile DriveSan Diego, CA 92182-1309Tel. +1 619 594 1053Fax +1 619 594 2654E-mail [email protected]

…

San Francisco Section

Chair: Jim McTigueTel. +1 650 846 1178E-mail [email protected]

Vice Chair:Gene RadzikTel. +1 415 558 0284E-mail [email protected]

Secretary (Section Contact):Conrad Cooke231 Cowper StreetPalo Alto, CA 94301Office Tel. +1 650 846 1132Home Tel. +1 650 321 0713E-mail [email protected]

Treasurer:Annemarie Staepelaere

1993 Plymouth Street, #8Mountain View, CA 94043Tel. +1 650 964 2563E-mail [email protected]

Committee:Gary BrownAaron HipplePaul HowardJohathan KayRon KnappJP LesterTed MarshBob MegantzThomas Merklein

…

San Francisco State University Section(Student)

Chair:Monika Mayer-KielmannTel. +1 415 337 1771E-mail [email protected] Chair:Heather BradleyTel. +1 415 643 7265E-mail [email protected]

Secretary:Mark HopperTel. +1 415 584 7694E-mail [email protected]

Treasurer:Jade Paget-SeekinsTel. +1 415 661 3398E-mail [email protected]

Committee:Robert ArreolaTim BurbyBill CarpenterDani DoscherDonald GoreJason KuczenskiTravis LaMettereyJon MeyerRyan OlsenSaturn PaduaHilson ParkerTodd PerezKim Wilkes


Faculty Advisor:John BarsottiAES Student SectionSan Francisco State UniversityBroadcast and Electronic Communication

Arts Department1600 Halloway AvenueSan Francisco, CA 94132Tel. +1 415 338 1507E-mail [email protected]

…

Stanford University Section (Student)

Chair:Scott CannonTel. +1 650 346 4556Fax +1 650 723 8468E-mail [email protected]

Vice Chair:Bert Schiettecatte Tel. +1 650 497 3066Fax +1 650 723 8468E-mail [email protected]

Secretary:Carr WilkersonTel. +1 650 497 2184Fax +1 650 723 8468E-mail [email protected]

Treasurer:Sunjay LadTel. +1 650 497 4839Fax +1 650 723 8468E-mail [email protected]

Faculty Sponsor:Jay KadisStanford AES Student SectionStanford UniversityCCRMA/Department of MusicStanford, CA 94305-8180Tel. +1 650 723 4971Fax +1 650 723 8468E-mail [email protected]

…

University of Southern California(Student)Chair:Sean BartonTel. +1 213 948 7800E-mail [email protected]

Vice Chair:Oliver HildTel. +1 818 438 4490E-mail [email protected]

Secretary:Chris MendezTel. +1 563 505 2675E-mail [email protected]

Treasurer:Brette ButtrillTel. +1 213 764 2856E-mail [email protected]

Faculty Advisor:Kenneth LopezAES Student SectionUniversity of Southern California840 West 34th StreetLos Angeles, CA 90089-0851Tel. +1 213 740 3224Fax +1 213 740 3217E-mail [email protected]

COLORADO

Colorado Section


Chair:Richard SandersSalt Productions Inc.725 Mariposa StreetDenver, CO 80204Tel. +1 303 825 1900E-mail [email protected]

Vice Chair:Duane Wise2201 Pearl Street, #311Boulder, CO 80302Tel. +1 303 443 7905E-mail [email protected]

Secretary:Roy Pritts2873 So. Vaughn WayAurora, CO 80014Tel. +1 303 369 9514E-mail [email protected]

Treasurer:Justin A. Davis3351 South WinstonAurora, CO 80013Tel. +1 720 870 2758E-mail [email protected]

Committee:Len KusovacDanny L. MatthewsMike PappasDavid L. RickKen Toal

…

Denver Section (Student)

Chair:Michael Shaw6661 S. TrailwayParker, CO 80134Tel. +1 638 6571E-mail [email protected]

Vice Chair:Liz ShepardP. O. Box 481281Denver, CO 80248Tel. +1 303 863 7125E-mail [email protected]

Secretary:Everett Moran1355 Corona St.Denver, CO 80218Tel. +1 303 813 8410E-mail [email protected]

Treasurer:Nick Sullivan1680 Steele #A6Denver, CO 80206Tel. +1 303 388 0928E-mail [email protected]


Faculty Advisor:Roy Pritts

AES Student SectionUniversity of Colorado at DenverDepartment of Professional StudiesCampus Box 162P.O. Box 173364Denver, CO 80217-3364Tel. +1 303 556 2795Fax +1 303 556 2335E-mail [email protected]

OREGON

Portland

Chair:Duke Aguiar14572 S.W. Rask TerraceTigard, OR 97224-0808Tel. +1 503 590 5122Fax +1 503 590 7815

Vice Chair:Cal Perkins12354 N.W. Kearney StreetPortland, OR 97229Tel. +1 503 643 4919Fax +1 503 526 0798

Secretary:Tony Dal MolinAudio Precision, Inc.5750 S.W. Arctic DrivePortland, OR 97005Tel. +1 503 627 0832Fax +1 503 641 8906E-mail [email protected]

Treasurer:Gordon Long1660 S.W. Wellington AvenuePortland, OR 97225Tel. +1 503 644 4530Committee:Pete AlwardRichard Cabot

UTAH

Brigham Young University Section(Student)

Faculty Advisor:Timothy LeishmanBYU-AES Student SectionDepartment of Physics and Astronomy Brigham Young UniversityProvo, UT 84602Tel. +1 801 422 4612Fax +1 801 422 0553

Chair:Gordon Dix665 N. 100 E. #8Provo, UT 84606Tel. +1 801 342 9239E-mail [email protected]

Vice Chair:Thomas Purdy630 N. 400 E.

Provo, UT 84606Tel. +1 801 607 2745E-mail [email protected]

Secretary:Lance Locey284 E. 600 No. # 6Provo, UT 84606Tel. +1 801 374 2570E-mail [email protected]

Treasurer:Sarah Rollins660 No. 200 E. # 18Provo, UT 84606Tel. +1 801 422 4612E-mail [email protected]

Committee:Ben FaberTodd KitchenDave NutterMicah ShepherdRichard Watkins

…

Utah Section

Chair:Deward Timothyc/o Poll Sound4026 South MainSalt Lake City, UT 84107Tel. +1 801 261 2500Fax +1 801 262 7379

Vice Chair:Ed Jones50 East North TempleSalt Lake City, UT 84150Tel. +1 801 531 4076

Treasurer:Hurschell Urie3160 Iowa AvenueOgden, UT 84403Tel. +1 801 393 8738

Committee:Richard Fullmer

WASHINGTON

Pacific Northwest Section

Chair:Rick ChinnUneeda AudioE-mail [email protected]

Vice Chair: Dave Tosti-LaneCornish College of the Arts710 East Roy StreetSeattle, WA 98102E-mail [email protected]

Secretary:Gary Louie




University of Washington School of MusicP.O. Box 353450Seattle, WA 98195Office Tel. +1 206 543 1218Fax +1 206 685 9499E-mail [email protected]

Treasurer:Dan MortensenDansound, Inc.P.O. Box 75294Seattle, WA 98125Tel. +1 206 525 2113E-mail [email protected]

Committee:Dave FranzwaBob GudgelAurika HaysRon HyderMichael MateskyMark RogersLee SilberkleitRick SmargiassiLindsay Smith

…

The Art Institute of Seattle Section(Student)

Chair:Blake White

Vice Chair:Austin Sousa

Secretary/Treasurer:Keith Henry

All correspondence toFaculty Advisor:David G. ChristensenAES Student SectionThe Art Institute of Seattle2323 Elliott AvenueSeattle, WA 98121-1622Tel. +1 206 448 0900E-mail [email protected]

CANADA

Alberta Section

Chair:Theresa LeonardP.O. Box 1020, Station 23Banff, Alberta T1L 1H5, Canada Tel. +1 403 762 6648Fax +1 403 762 6338E-mail [email protected]

Vice Chair:Chris BradleyP.O. Box 1020, Station 23Banff, Alberta T1L 1H5, CanadaE-mail [email protected]

Secretary:Frank Lockwood

AES Alberta SectionSuite 404 815 - 50 Avenue S.W.Calgary, Alberta T2S 1H8, CanadaHome Tel. +1 403 703 5277Fax +1 403 762 6665E-mail [email protected]

Treasurer:Lyle FishP.O. Box 1020, Station 21Banff, Alberta T1L 1H5, CanadaTel. +1 403 762 6261Fax +1 403 762 6334E-mail [email protected]

Committee:Marie EbbingJoe Missio

…

Vancouver Section

Chair:Gary Osborne Tel. +1 604 461 5471 Fax +1 604 461 5473 E-mail [email protected]

Vice Chair: Reid King Tel. +1 604 224 7123Fax +1 604 224 2296 E-mail [email protected]

Secretary:Peter JanisC-Tec#114, 1585 BroadwayPort Coquitlam, B.C. V3C 2M7, CanadaTel. +1 604 942 1001Fax +1 604 942 1010E-mail [email protected]

Treasurer:Gregg Gorrie Tel. +1 604 298 5400 E-mail [email protected]

Past Chair: Martin Huhn Tel. +1 604 709 0711E-mail [email protected]

Committee:Hamid BouhiouiDave FirbyMark GordonDavid KellnMarc SalvasLucas Truman

…

Vancouver Student Section

Chair:Ryan Powell

Vice Chair:Ryan MarchandE-mail [email protected]

Secretary/Treasurer:Juan-Carlos Gurellio


Faculty Advisor:Gregg Gorrie c/o CDIS3264 Beta AvenueBurnaby, B.C. V5G 4K4, CanadaTel. +1 604 298 5400 E-mail [email protected]

Vice President:Søren BechBang & Olufsen a/sCoreTechPeter Bangs Vej 15DK-7600 Struer, DenmarkTel. +45 96 84 49 62Fax +45 97 85 59 50E-mail [email protected]

BELGIUM

Belgian Section

Chair:Edgar P. M. PeetersWolec Electronics pbvaLeuvense steenweg 181BE-1932 S. Stevens-Woluwe, BelgiumTel./Fax +32 2 720 0218

Secretary:Korneel M. L. TaeckensTel. +32 2 345 7971Fax +32 2 345 3419

Treasurer (Section Contact):Hermann A. O. WilmsAES Europe Region OfficeZevenbunderslaan 142, #9BE-1190 Vorst-Brussels, BelgiumTel. +32 2 345 7971Fax +32 2 345 3419

Committee:Ben EemanGérard LambertHugo J. Libaers

DENMARK

Danish Section

Chair:

Michael Kaaber HarritDR, TVBYENMørkhøjvej 500DK-2860 Søborg, DenmarkE-mail [email protected]

Vice Chair:Daniel A. van Kranendonk

NORTHERN REGION, EUROPE

Heisesgade 2DK-2100 Copenhagen Ø, DenmarkE-mail [email protected]

Secretary:Knud Bank ChristensenSkovvej 2DK-8550 Ryomgård, DenmarkTel. +45 87 42 71 46Fax +45 87 42 70 10E-mail [email protected]

Treasurer:Subir (Pram) K. PramanikSarpsborgvej 56DK-7600 Struer, DenmarkE-mail [email protected]

Committee:Eddy Bøgh BrixenSøren L. JørgensenPreben KvistThomas Kyhn

…

Danish Student Section

Section Contact:Knud Bank ChristensenSkovvej 2DK-8550 Ryomgård, DenmarkTel. +45 87 42 71 46Fax +45 87 42 70 10E-mail [email protected]

FINLAND

Finnish Section

Chair:Jyri HuopaniemiNokia Research CenterP.O. Box 407FI-00045 Nokia Group, FinlandTel. +358 9 43761 Fax +358 9 4376 7133E-mail [email protected]

Vice Chair:Nick ZacharovNokia Research CenterP.O. Box 100FI-33721 Tampere, FinlandTel. +358 7180 35786Fax +358 7180 35899E-mail [email protected]

Secretary:Kalle KoivuniemiNokia Research CenterP.O. Box 100FI-33721 Tampere, Finland Tel. +358 7180 35452Fax +358 7180 35897E-mail [email protected]

Treasurer:Kari JaksolaOskarintie 5FI-00930 Helsinki, Finland

Tel. +358 400 420682Fax +358 9 3446 0660E-mail [email protected]

Committee:Juha BackmanPetri Mäntysalo Timo Peltonen Olli Salmensaari

NETHERLANDS

Netherlands Section

Chair:Cees WagenaarVan der Glashof 15NL-3816 MN Amersfoort, NetherlandsTel./Fax +31 33 470 14 71E-mail [email protected]

Vice Chair:Peter SwarteGraaf Adolfstraat 85NL-5616 BV Eindhoven, NetherlandsTel. +31 40 255 08 89E-mail [email protected]

Secretary:Rinus BooneVoorweg 105ANL-2715 NG Zoetermeer, NetherlandsTel. +31 15 278 14 71, +31 62 127 36 51Fax +31 79 352 10 08E-mail [email protected]

Treasurer:Tom MagchielseKoningstraat 18NL-1213 AX Hilversum, NetherlandsTel./Fax +31 35 621 16 17E-mail [email protected]

Committee:Bert KraaijpoelTin JonkerDaniel SchobbenEvert StartWerner de Bruijn (Student Member)

…

Netherlands Student Section

Chair:Werner de BruijnKorvezeestraat 541NL-2628 CZ Delft, NetherlandsHome Tel. +31 15 2622995Office Tel. +31 15 2782021E-mail [email protected]

Vice Chair:Joeri SaalBellamystraat 17Amsterdam, Netherlands E-mail [email protected]

Secretary:Dirk Fischer

AES Student SectionGroenewegje 143aDen Haag, NetherlandsHome Tel. +31 70 3885958E-mail [email protected]

Treasurer:Ruud JehaeCuijkstraat 30NL-6844 AK Arnhem, NetherlandsHome Tel. +31 26 3818560E-mail [email protected]

Committee:Maurik van den Steen

NORWAY

Norwegian Section

Chair:Asbjörn SaeböAstri Aasens veg 8 BNO-7051 Trondheim, NorwayTel. +47 73 93 78 69E-mail [email protected]

Secretary:Jan Erik JensenNöklesvingen 74NO-0689 Oslo, NorwayOffice Tel. +47 22 24 07 52Home Tel. +47 22 26 36 13Fax +47 22 24 28 06E-mail [email protected]

Treasurer:Tore HaugTandbergveien 45NO-1929 Auli, NorwayOffice Tel. +47 22 90 56 78Fax +47 22 90 56 71E-mail [email protected]

Committee:Mark Drews

RUSSIA

All-Russian State Institute ofCinematography Section (Student)

Faculty Sponsor:Leonid SheetovAES Student SectionAll-Russian State Institute of

Cinematography (VGIK)W. Pieck Street 3RU-129226 Moscow, RussiaTel. +7 095 181 3868Fax +7 095 187 7174E-mail [email protected]

...Moscow Section

Chair (Section Contact):Michael LannieResearch Institute for Television and

RadioAcoustic Laboratory



12-79 Chernomorsky bulvarRU-113452 Moscow, RussiaTel. +7 095 2502161, +7 095 1929011Fax +7 095 9430006E-mail [email protected]

Vice Chair:Alexander GaidarovTel. +7 095 1269875E-mail [email protected]

Secretary/Treasurer:Tatiana MaksimovaTel. +7 095 2220068E-mail [email protected]

Committee:Yuri BogdanovVladimir GinzburgValentin KostinBoris NekrasovLeonid ShitovAlexander ShriebmanDmitry Svoboda

...St. Petersburg Section

Chair:Irina A. AldoshinaSt. Petersburg University of

TelecommunicationsGangutskaya Street 16, #31RU-191187 St. Petersburg, RussiaTel. +7 812 272 4405Fax +7 812 316 1559E-mail [email protected]

Vice Chair:Andrey A. AkhmatovTel. +7 812 295 2406Fax +7 812 230 3736

Secretary:Svetlana PetrovaBaltic State Technical University1st Krasnoarmeyskaya St., 1RU-198005, St. Petersburg, RussiaTel. +7 812 110 1573Fax +7 812 316 1559E-mail [email protected]

...

St. Petersburg Student Section

Chair:Evgeny SavelievAES Student SectionBaltic State Technical University1st Krasnoarmeyskaya St., 1RU-198005 St. Petersburg, RussiaTel. +7 812 110 1573Fax +7 812 316 1559E-mail [email protected]

Secretary:Irina ZadiraevaSt. Petersburg University of Cinema and

Television

22 Bukharestskaya Str.RU-191126, St. Petersburg, RussiaTel. +7 812 255 0143

Faculty Advisor:Natalia V. TyurinaProsvescheniya pr., 41, 185RU-194291 St. Petersburg, RussiaTel./Fax +7 812 595 1730Fax +7 812 316 1559E-mail [email protected]

SWEDEN

Swedish Section

Chair:Olov KarlssonBjoernsonsgatan 166SE-16845, Bromma, SwedenTel. +46 708877784E-mail [email protected]

Vice Chair:Johan VävareBox 15153SE-104 65 Stockholm, SwedenTel. +46 8 644 25 14Fax +46 8 641 67 91E-mail [email protected]

Secretary:Mikael OlssonStationsvägen 44SE-19730, Bro, SwedenTel. +46 7 0622 90 04Fax +46 8 5824 95 50E-mail [email protected]

Treasurer:Ingemar OhlssonAudio Data LabKatarinavägen 22SE-116 45 Stockholm, SwedenTel. +46 8 644 58 65Fax +46 8 641 67 91E-mail [email protected]

Web Masters:Janne AnderssonKaj Sandström

Committee:Lennart NilssonSten Wahlström

...

University of Luleå-Piteå Section(Student)

Chair:Christian AnshelmAnkarskatevägen 89LS-94134 Piteå, Sweden

Vice Chair:Nina HallstromAnkarskatevägen 81AS-941 34 Piteå, SwedenE-mail [email protected]

SecretaryPeter HeddelinAnkarskatevägen 80LS-941 64, Piteå, Sweden

Treasurer:Anders ErikssonLäkarvagen 10S-931 41, Sellefrea, Sweden


Faculty Sponsor:Lars HallbergAES Student SectionUniversity of Luleå-PiteåSchool of MusicBox 744S-941 34 Piteå, SwedenTel. +46 911 726 27Fax +46 911 727 10E-mail [email protected]

UNITED KINGDOM

British Section

Chair:Mark YongeWoodlands, Goodwood RiseMarlow, Bucks. SL7 3QEUnited KingdomTel./Fax +44 1628 440732E-mail [email protected]

Vice Chair:Steve Harris2 Longford CloseCamberley GU15 2NE, United KingdomTel. +44 7710 657828Email [email protected]

Secretary:Heather LaneAudio Engineering SocietyP.O. Box 645Slough SL1 8BJ, United KingdomTel. +44 1628 663725Fax +44 1628 667002E-mail [email protected]

Past Chair:John Nunn1 Rowlatt RoadWilmington, Dartford DA2 7PSUnited KingdomTel./Fax +44 1322 229195Email: [email protected]

Committee:Kendall Castor-PerryHoward FarrerJohn GrantTim SheltonChris SleightPaul TroughtonBob Walker

Vice President:Markus Erne

CENTRAL REGION, EUROPE


Scopein ResearchSonnmattweg 6CH-5000 AarauSwitzerlandTel. +41 62 825 09 19Fax +41 62 825 09 15E-mail [email protected]

AUSTRIA

Austrian Section

Chair:Werner Anton DeutschLiechtensteinstrasse 62AT-1090 Vienna, AustriaTel. +43 1 4277 29500, +43 1 4277 29501Fax +43 1 4277 9295E-mail [email protected]

Vice Chair:Nadja WallaszkovitsCarl-Reichert-Gasse 24AT-1170 Vienna, AustriaTel. +43 1 4277 29601, +43 664 1344300Fax +43 1 4277 9296E-mail [email protected]

Secretary:Franz LechleitnerLainergasse 7-19/2/1AT-1230 Vienna, AustriaOffice Tel. +43 1 4277 29602Fax +43 1 4277 9296E-mail [email protected]

Treasurer:Ewald KerschbaumHohe Wandstrasse 3/7AT-2346 Ma. Enzersdorf, AustriaTel. +43 2236 49592, +43 676 5233678E-mail [email protected]:Erhard AschingerFelix DreherGerhard GraberRobert HöldrichErnst KöhlerAlfred Kraker Manfred Lenger Karl PeschelHeinrich PichlerDietrich SchüllerNorbert SobolMichael StraußGregor Widholm

…Graz Section (Student)

Chair:Daniel HojkaTel. +43 650 64 71 049E-mail [email protected]

Vice Chair:Henning BosbackTel. +43 316 67 37 26E-mail [email protected]

Secretary:Holger Hiebel

Tel. +43 650 46 54 374E-mail [email protected]

Treasurer:Peter PlessasTel. +43 664 35 07 475E-mail [email protected] [email protected]

Faculty Sponsor (Section Contact):Robert HöldrichInstitut für Elektronische Musik und

AkustikInffeldgasse 10AT-8010 Graz, AustriaTel. +43 316 389 3172Fax +43 316 389 3171E-mail [email protected]

…Vienna Section (Student)

Chair:Nils KirchhoffE-mail [email protected]

Vice Chair:Sebastian Chonion E-mail [email protected]

Secretary:Felix Dreher E-mail [email protected]:Andreas ZieglerE-mail [email protected]


Faculty Sponsor:Jürg JecklinVienna Student SectionUniversität für Musik und Darstellende

Kunst WienInstitut für Elektroakustik und

Experimentelle MusikRienösslgasse 12AT-1040 Vienna, AustriaTel. +43 1 587 34 78Fax +43 1 587 34 78 20E-mail [email protected]

CZECH REPUBLIC

Czech Section

Chair:Pavel BaladranZa Zahradami 1400CZ-253 01 Hostivice, Czech Republic Home Tel. +420 2 20982259Office Tel. +420 2 21553256 (Czech

Radio)Fax +420 2 21553253E-mail [email protected]

Vice Chair:Zdenek KesnerU Kanalky 5CZ-120 00 Prague 2, Czech Republic Home Tel. +420 2 22726393E-mail [email protected]

Secretary/Treasurer:Jiri OcenasekDejvicka 36CZ-160 00 Prague 6, Czech Republic Home Tel. +420 2 24324556E-mail [email protected]

Committee:Jiri FolvarcnyMiroslav LukesJiri Schimmel

…

Czech Republic Student Section

Chair:Jiri SchimmelE-mail [email protected]

Vice Chair:Miroslav LukesE-mail [email protected]


Faculty Advisor:Libor HusníkAES Student SectionCzech Technical University at PragueTechnická 2166 27 Prague 6, Czech RepublicTel. +420 2 2435 2115E-mail [email protected]

GERMANY

Aachen Section (Student)

Chair:Aulis TelleVice Chair:Steven Phee

Secretary:Christian Budde

Faculty Sponsor:Michael VorländerInstitut für Technische AkustikRWTH AachenTemplergraben 55D-52065 Aachen, GermanyTel. +49 241 807985Fax +49 241 8888214E-mail [email protected]

Berlin Section (Student)

Chair (Section Contact):Bernhard GüttlerZionskirchstrasse 14DE-10119 Berlin, GermanyTel. +49 30 4404 72 19Fax +49 30 4405 39 03E-mail [email protected]

Vice Chair:Sebastian GablerTel./Fax +49 30 283 16 48E-mail [email protected]



Secretary:Ulrike SchwarzTel./Fax +49 30 694 7105E-mail [email protected]

Faculty Sponsor:Johann-Nikolaus MatthesAES Student SectionHdK-BerlinFasanenstr. 1bDE-10629 Berlin, GermanyTel. +49 30 831 53 66Fax +49 30 88 32 93 35

…Central German Section

Chair/Secretary/Treasurer:Ernst-Joachim VölkerInstitut für Akustik und BauphysikKiesweg 22-24DE-61440 Oberursel, GermanyTel. +49 6171 75031 Fax +49 6171 85483E-mail [email protected]

Committee:D. BraunToning Thomas HeidelMichael KeyhlAxel RoyThomas Sporer

…

Darmstadt Section (Student)

Chair:Tom LanglotzTel. +49 6151 154289E-mail [email protected]

Vice Chair:Richard Schulz-AmlingTel. +49 6151 426404E-mail [email protected]

Secretary/Treasurer:Christian HardersTel. +49 6151 919599E-mail [email protected]


Faculty Sponsor:G. M. SesslerAES Student SectionTechnical University DarmstadtInstitut für ÜbertragungstechnikMerkstr. 25DE-64283 Darmstadt, GermanyTel. +49 6151 162869E-mail [email protected]

...

Detmold Section (Student)

Chair:Hendrik ManookE-mail [email protected]

Vice Chair:Christian StruckE-mail [email protected]


Faculty Advisor:Andreas MeyerAES Student SectionErich Thienhaus InstitutTonmeisterausbildung Hochschule für

Musik DetmoldNeustadt 22DE-32756 Detmold, GermanyTel./Fax +49 5231 975639E-mail [email protected]

...

Düsseldolf Section (Student)

Chair:Stephan CahenTel. +49 234 58 19 09Fax +49 234 58 40 74 2E-mail [email protected]

Vice Chair:Andreas TurnwaldTel. +49 211 49 07 96E-mail [email protected]

Secretary/Treasurer (Section Contact):Ludwig KuglerAES Student SectionBilker Allee 126DE-40217 Düsseldorf, GermanyTel. +49 211 3 36 80 38E-mail [email protected]

Faculty Sponsor:Dieter BraunTel. +49 221 4 30 14 43Fax +49 221 9 43 50 57E-mail [email protected]

...

Ilmenau Section (Student)

Chair:Ralf GeigerTel. +49 3677 69 4341Fax +49 3677 69 4399E-mail [email protected]

Vice Chair:Sascha RißmannScheffelstraße 898693 Ilmenau, GermanyTel. +49 3677 78 90 90E-mail [email protected]

Secretary/Treasurer:Christian RichterTel. +49 3677 207707E-mail [email protected]


Faculty Sponsor:Karlheinz Brandenburg

AES Student SectionInstitut für MedientechnikPF 10 05 65DE-98684 Ilmenau, GermanyTel. +49 3677 69 2676Fax +49 3677 69 1255E-mail [email protected]

...

North German Section

Chair:Reinhard O. SahrEickhopskamp 3DE-30938 Burgwedel, GermanyTel. +49 5139 4978Fax +49 5139 5977E-mail [email protected]

Vice Chair:Johannes RichterAschaffenburgerstrasse 14DE-10779 Berlin, GermanyTel./Fax +49 30 218 27 17

Secretary/Treasurer:Volker W. Rheniusc/o Sennheiser Electronic GmbH & Co. KGPostfach 10 02 64DE-30900 Wedemark, GermanyTel. +49 5130 600 345Fax +49 5130 600 330

…

South German Section

Chair:Günther TheileInstitut für RundfunktechnikFloriansmühlstrasse 60DE-80939 Munich, GermanyTel. +49 89 323 99 324Fax +49 89 323 99 351E-mail [email protected]

Vice Chair:Jens-Helge HergesellFachhochschule StuttgartNobelstrasse 10DE-70569 Stuttgart, GermanyTel. +49 711 685 2871Fax +49 711 685 6694E-mail [email protected]

Secretary/Treasurer:Gerhard E. PicklappLandshuter Allee 162DE-80637 Munich, GermanyTel. +49 89 15 16 17Fax +49 89 157 10 31E-mail [email protected]

Committee:Georg BeyerAlfred SchaumbergerGerhard StollMichael ThomasMartin Wöhr


HUNGARY

Hungarian Section

Chair:Ferenc György TakácsSzellö u. 2. VII. 18.HU-1035 Budapest, HungaryHome Tel. +36 1 368 47 70Office Tel. +36 1 463 20 47Fax +36 1 463 32 66E-mail [email protected]

Honorary Chair:Gábor HeckenastErzsébet királynö ut 2.HU-1146 Budapest, HungaryTel./Fax +36 1 341 07 04E-mail [email protected]

Secretary:István MatókRona u. 102. II. 10HU-1149 Budapest, HungaryHome Tel. +36 30 900 1802Fax +36 1 383 24 81E-mail [email protected]

Treasurer:Attila KissDamjanich út 3.HU-1213 Budapest, HungaryHome Tel. +36 1 276 45 62Mobile (Cellaphone) +36 30 442 57 32Office Tel. +36 1 387 95 10E-mail [email protected]

Committee:János GranátImre GáspárSándor Steinbach

LITHUANIA

Lithuanian Section

Chair (Section Contact):Vytautas J. StauskisVilnius Gediminas Technical UniversityTraku 1/26, Room 112LT-2001 Vilnius, LithuaniaTel. +370 5 262 91 78Fax +370 5 261 91 44E-mail [email protected]

Vice Chair:Audvydas StaskeviciusVilnius Gediminos Technical UniversityTraku 1/26, Room 112LT-2001 Vilnius, LithuaniaTel. +370 2 700 482Fax +370 2 700 114E-mail [email protected]

Secretary: Kestutis JuskeviciusVilnius Institut of Mathematics and

InformaticsA. Gostauto 12LT-2600 Vilnius, LithuaniaTel. +370 2 614 040


Treasurer:Valdas OzeraitisVilnius Institut of Mathematics and

InformaticsTraku 1/26, Room 112LT-2001 Vilnius, LithuaniaTel. +370 2 614 040Fax +370 2 619 905E-mail [email protected]

Committee:Romualdas ApanaviciusVytaytas BiciunasBenjaminas CerniusVaimantas GirniusAleksandras JagnetinskisLoreta KemezyteRomualdas KurilaVytautas LasauskaHenrikas MiciuleviciusMindaugas NevardauskasEugenijus PileckisInga SitaiteRitoldas SukysGvidas SvilysLaimutis TelksnysRimante Vaskyte

POLAND

Polish Section

Chair:Jan A. AdamczykUniversity of Mining and MetallurgyDept. of Mechanics and Vibroacousticsal. Mickiewicza 30PL-30 059 Cracow, PolandTel. +48 12 617 30 55Fax +48 12 633 23 14E-mail [email protected] Chair:Wojciech Makowskial. Niepodlegtosci 77/85PL-00 977 Warsaw, PolandTel. +48 22 645 90 01Fax +48 22 645 59 06

Secretary:Piotr KrzyworzekaUniversity of Mining and MetallurgyDept. of Mechanics and Vibroacousticsal. Mickiewicza 30PL-30 059 Cracow, PolandTel. +48 12 419 13 02E-mail [email protected]

Treasurer:Piotr KleczkowskiUniversity of Mining and MetallurgyDept. of Mechanics and Vibroacousticsal. Mickiewicza 30PL-30 059 Cracow, PolandTel. +48 12 413 30 07Fax +48 12 633 23 14E-mail [email protected]

Committee:Andrzej Czyzewski

Andrzej DobruckiTadeusz FideckiBozena Kostek

Board of Control:Krzysztof Rudno-RudzinskiMaria TajchertNikodem Wolk-Laniewski

Fellow Arbitration Committee:Marianna SankiewiczKrzysztof WojtowiczTomasz Zebrowski

...

Technical University of Gdansk Section(Student)

Chair:Piotr SzczukoTel. +48 58 347 19 67E-mail [email protected]

Secretary:Pawel ZwanTel. +48 58 347 23 98E-mail [email protected]

Treasurer:Piotr OdyaTel. +48 58 347 23 98E-mail [email protected]

Member of Council:Przemysaw Maziewskitel: +48 58 347-23-01e-mail: [email protected]

Faculty Advisor: Dr. Bozena KostekE-mail [email protected] Address:AES Student SectionTechnical University of GdanskSound Engineering Dept. ul. Narutowicza 11/12PL-809 52 Gdansk, PolandTel. +48 58 3471301Fax +48 58 3471114

...

Wroclaw University of TechnologySection (Student)

Chair :Tomasz NowickiTel. +48 501 101867E-mail [email protected]

Vice Chair:Marcin KaczmarekTel. +48 501 184163E-mail [email protected]

Secretary:Katarzyna KokottE-mail [email protected]



Treasurer:Marcin MatlakTel. +48 501 144291E-mail [email protected]

Faculty Sponsor:Andrzej B. DobruckiAES Student SectionInstitute of Telecommunications and

AcousticsWroclaw University of TechnologyWybrzeze Wyspianskiego 27PL-503 70 Wroclaw, PolandTel. +48 71 320 30 68Fax +48 71 320 31 89E-mail [email protected]

REPUBLIC OF BELARUS

Belarus Section

Chair:Alexander PetrovskiBelarusian State University of Informatics

and Radioelectronicsvul. Petrusya Brouki 6BY-220027 Minsk, Republic of BelarusTel. +375 17 231 29 10Fax +375 17 231 09 14E-mail [email protected]

Vice Chair/Secretary:Valery ShalatoninBelarusian State University of Informatics

and Radioelectronicsvul. Petrusya Brouki 6BY-220027 Minsk, Republic of BelarusTel. +375 17 239 80 95Fax. +375 17 231 09 14E-mail [email protected]

Treasurer:Alexander TameloBelarusian State University of

Informatics and Radioelectronicsvul. Petrusya Brouki 6BY-220027 Minsk, Republic of BelarusTel. +375 17 239 80 95Fax +375 17 231 09 14E-mail [email protected]

Committee:Valery CherdyntsevValentin MuravjevMichail Zorka

SLOVAK REPUBLIC

Slovakian Republic Section

Vice Chair:Peter GranecNam. SNP 2377/7SK-701 01 Malacky, Slovak RepublicTel. +421 703 7726 311

Secretary:Richard VarkondaCentron Slovakia Ltd.Podhaj 107SK-841 03 Bratislava, Slovak RepublicTel. +421 7 6478 0767


Treasurer:Jan JamrichSlovensky rozhlasMytna 1P.O. Box 55SK-817 55 Bratislava, Slovak RepublicTel. +421 5727 3295Fax +421 5249 0687E-mail [email protected]

SWITZERLAND

Swiss Section

Chair:Attila KaramustafaogluE-mail

[email protected]

Vice Chair:Terry NelsonE-mail [email protected]

Secretary:Joël GodelE-mail [email protected]

Treasurer:Alain RouxE-mail [email protected]

Committee:Véronique AdamPatrick BoehmWalter KoellerGabriel Leuzinger

Mailing Address:AES Swiss SectionSonnmattweg 6CH-5000 Aarau, Switzerland

UKRAINE

Ukrainian Section

Chair (Section Contact):Valentin AbakumovNational Technical University of UkraineKiev Politechnical InstitutePolitechnical Street 16Kiev UA-56, UkraineTel./Fax +38 044 2366093

Vice Chair:Vladimir JankovoyTel. +38 044 2746093

Secretary:Yuri YablonovskyTel./Fax +38 044 2746093

Mailing Address:AES SectionNational Technical University of UkraineKiev Politechnical InstituteProspect Peremogi 37Kiev UA-56, UkraineE-mail [email protected]

Vice President:Daniel ZalayConservatoire de ParisDept. SonFR-75019 Paris, FranceOffice Tel. +33 1 40 40 46 14Fax +33 1 40 40 47 68E-mail [email protected]

BOSNIA–HERZEGOVINA

Bosnia–Herzegovina Section

Chair (Section Contact):Jozo TalajicBulevar Mese Selimovica 12BA-71000 SarajevoBosnia–HerzegovinaTel. +387 33 455 160Fax +387 33 455 163E-mail [email protected]

Vice Chair:Nermin DizdarevicMustafe Dovadzije 11/aBA-71000 SarajevoBosnia–HerzegovinaTel. +387 33 271 610Fax +387 33 233 127E-mail [email protected]

Secretary:Bojan StjepanovicBulevar Mese Selimovica 12BA-71000 SarajevoBosnia–HerzegovinaTel. +387 33 455 160Fax +387 33 455 163E-mail [email protected]:Elvir SurkovicBulevar Mese Selimovica 12BA-71000 SarajevoBosnia–HerzegovinaTel. +387 33 461 517Fax +387 33 644 025E-mail [email protected]

BULGARIA

Bulgarian Section

Chair:Ivan Valchev46A, Raiko Aleksiev St.BG-1113 Sofia, BulgariaTel. +359 2 73 48 73Fax +359 2 971 9063

Secretary:Konstantin D. KounovBulgarian National RadioTechnical Department4 Dragan Tzankov Blvd. BG-1040 Sofia, BulgariaTel. +359 2 65 93 37, +359 2 9336 6 01Fax +359 2 963 1003E-mail [email protected]

Treasurer:Hristo Dimchev

SOUTHERN REGION, EUROPE


P.O. Box 1072BG-1000 Sofia, BulgariaTel. +359 2 59 63 77Fax +359 2 958 1011

Technical Committee Chair:Georgi Hlebarov

Auditing Committee Chair:Krum Petrov

CROATIA

Croatian Section

Chair:Branko SomekFakultet Elektrotehnike i RacunarstvaUnska 3HR-10000 Zagreb, CroatiaTel. +385 1 612 96 40Fax +385 1 612 98 62E-mail [email protected]

Vice Chair:Leo RahelicAVCLastovska 23HR-10000 Zagreb, CroatiaTel. +385 1 612 46 22Fax +385 1 611 13 16E-mail [email protected]

Secretary:Silvije StamacHrvatski RadioPrisavlje 3HR-10000 Zagreb, CroatiaTel. +385 1 634 28 81Fax +385 1 611 58 29E-mail [email protected]

Treasurer:Biserka FlajpanHrvatski RadioPrisavlje 3HR-10000 Zagreb, CroatiaTel. +385 1 634 31 22Fax +385 1 611 58 29E-mail [email protected]

Committee:Radomir DavidovskyHrvoje DomitrovicSinisa Fajt

...

Croatian Student Section

Chair:Jurica BaricE-mail [email protected]

Vice Chair:Krunoslav StasicE-mail [email protected]

Secretary:Goran GrgacE-mail [email protected]

Treasurer:Tomislav IvankovicE-mail [email protected]

CommitteeVladimir CepericTvrtko MandicGoran Thomas


Faculty Advisor:Hrvoje DomitrovicAES Student Section Faculty of Electrical Engineering

and ComputingDepartment of Electroacoustics (X. Fl.)Unska 3HR-10000 Zagreb, CroatiaTel. +385 1 6129 640Fax +385 1 6129 852E-mail [email protected]

FRANCE

Conservatoire de Paris Section(Student)

Chair:Marc Larcher22 BIS, Avenue de SuffrenFR-75015 Paris, FranceTel. +33 1 47 34 12 28

Secretary (Section Contact):Alessandra Galleron36, Avenue ParmentierFR-75011 Paris, FranceTel. +33 1 43 38 15 94E-mail [email protected]

Secondary Contact:Blaise Chabanis14, rue de La FaisandericFR-77200 Torcy, FranceE-mail [email protected]

Faculty Advisor:Michael Williams

School Tel. (Secretary):+33 1 40 40 45 56

...

French Section

Chair:Xavier MeynialInstitut d’Acoustique et de Mécanique Avenue Olivier MessianF-72085 Le Mans Cedex 9, France

Vice Chair:Daniel ZalayConservatoire de ParisDept. SonFR-75019 Paris, FranceOffice Tel. +33 1 40 40 46 14

Fax +33 1 40 40 47 68E-mail [email protected]

Secretary/Treasurer:Michael WilliamsIle du Moulin62 bis Quai de l’ArtoisF-94170 Le Perreux sur Marne, FranceTel. +33 1 48 81 46 32Fax +33 1 47 06 06 48E-mail [email protected]

...

Louis Lumière Section

Chair:Arnaud DelormeTel. +33 1 43 03 51 27, +33 6 12 78 21 95E-mail [email protected]

Vice Chair:Raphael KalfonTel. +33 1 43 03 26 50, +33 6 63 23 25 79E-mail [email protected]

Secretary (Section Contact):Alexandra Carr-BrownTel. +33 6 18 57 84 41E-mail [email protected]

Treasurer:Jerome SultanTel. +33 6 75 38 48 39E-mail [email protected] Advisor:Jean-Paul Bourre

Committee:Ludovic EliasFrançois GueurceTristan LaurinEdouard MorinVincent Vatoux

School Address:AES Student SectionEcole Nationale Supérieure

Louis Lumière7, allée du Promontoire, BP 22FR-93161 Noisy Le Grand Cedex, FranceTel. +33 1 48 15 40 10Fax +33 1 43 05 63 44

GREECE

Greek Section

Secretary:Vassilis TsakirisCrystal AudioAiantos 3a VrillissiaGR 15235 Athens, GreeceTel. + 30 2 10 6134767Fax + 30 2 10 6137010E-mail [email protected]

ISRAEL

Israel Section



Chair:Yoav GeyraThe Israel Sound Engineering School4 Rival StreetTel Aviv IL-67778, Israel

Secretary:Ben Bernfeld Jr.H. M. Acustica Ltd.20G/5 Mashabim St..IL-45201 Hod Hasharon, IsraelTel./Fax +972 9 7444099E-mail [email protected]

Treasurer:Jussi DiamantEltra Electronics Industries, Ltd.Ashdod, Israel

Committee:Emil BarMeir EshelAbraham GatSergio LibermanAkiva Melamed

ITALY

Italian Section

Chair:Gualtiero Berlinghinivia E. Wolf FerrariIT-20141 Milan, ItalyTel. +39 02 58431024 Fax +39 02 58440640E-mail [email protected]

Vice Chair:Florenzo Petittavia Veio 52IT-00183 Rome, ItalyTel. +39 06 69883147Fax +39 06 69883435E-mail [email protected]

Secretary:Carlo Perrettac/o AES Italian SectionPiazza Cantore 10IT-20134 Milan, ItalyTel.+39 338 9108768Fax +39 02 58440640 E-mail [email protected]

Treasurer:Roberto Beppatovia S. Maria 100IT-20090 S. Maurizio al Lambro,

Milan, ItalyTel. +39 02 27304401Fax +39 02 27309021E-mail [email protected]

Committee:B CacciaR. CalabreseW. ContiG. GoldoniG. Parladori

M. PellegrinatoC. Zuccatti

...

Italian Student Section

Chair: Daniele CrucilTel. +39 0432731956E-mail [email protected]

Vice Chair:Stefano RascioniTel. +39 040366803E-mail [email protected]

Secretary: Giacomo GanassiniTel. +39 0422959884E-mail

[email protected]

Treasurer: Stefano Bettin ToscanoTel. +39 040307450E-mail [email protected]

Faculty Advisor:Franco GrossiAES Student SectionViale San Daniele 29IT-33100 Udine, ItalyTel. +39 0432227527E-mail [email protected]

Committee:Nicola FabrioValerio IaccaMarco Sardi

PORTUGAL

Portugal Section

Executive BoardChair:António José da S. S. De OliveiraAcutron Electroacustica Lta.Urb. Quinta Nova Impasse 1 Lote 134PT-2685 Sacavem, PortugalE-mail [email protected]

Vice Chair:Aníbal João de Sousa FerreiraAv. Zeferino de Oliveira, 239PT-4560 Penafiel, PortugalE-mail [email protected]

Secretary:Rui Miguel Avelans CoelhoR. Paulo Renato 1, 2APT-2745-147 Linda-a-Velha, PortugalTel. +351 214145827E-mail [email protected]

Treasurer:Filipe Andrade SantosEstrada de Benfica 302 1 Dto.

PT-1500-098 Lisbon, PortugalE-mail [email protected]

Meetings BoardChair:Paulo Alexandre

Vice Chair:Aníbal João de Sousa Ferreira

Secretary:Celso J. De Albuquerque

Accounts BoardChair:José Manuel Neto Vieira

Vice Chair:João P. Jacinto

Secretary:Luis Gustavo Martins

ROMANIA

Romanian Section

Chair:Mihai IlieRadio Romania60-62 Grl. Berthelot StreetRO-79756 Bucharest, RomaniaTel. +40 1 312 20 58Fax +40 1 312 10 56

Vice Chair:Dan RadulescuRomacustica2 Zece Mase StreetRO-70319 Bucharest, RomaniaTel. +40 1 610 03 66

Secretary:Andrei PapudofRadio Romania60-62 Grl. Berthelot StreetRO-79756 Bucharest, RomaniaTel. +40 1 312 20 58Fax +40 1 312 10 56

Treasurer (Section Contact):Marcia TaiachinRadio Romania60-62 Grl. Berthelot StreetRO-79756 Bucharest, RomaniaTel. +40 1 303 12 07Fax +40 1 222 69 19E-mail [email protected]

Committee:Paul EnigarescuGheorghe NituDumitru Stanomir

SERBIA AND MONTENEGRO

Serbia and Montenegro Section

Chair:Petar PravicaFaculty of Electrotechnical Engineering


Bul. revolucije 73YU-11000 Belgrade, YugoslaviaTel. +381 11 3218 345Fax +381 11 3248 681E-mail [email protected]

Vice Chair:Milan OrlicRTS/Radio BelgradeHilandarska 2YU-11000 Belgrade, YugoslaviaTel. +381 11 3212 321Fax +381 11 3226 756E-mail [email protected]

Secretary:Tomislav StanojevicSava centreM. Popovica 9YU-11070 Belgrade, YugoslaviaTel. +381 11 311 1368Fax +381 11 605 578E-mail [email protected]

Treasurer:Goran SakotaAVC GroupGen. Zdanova 78YU-11000 Belgrade, YugoslaviaTel. +381 11 682 262Fax +381 11 643 073E-mail [email protected]

Committee:Zoran JerkovicMarina JovanovicZoran SevaljevicRobert Zentai

SLOVENIA

Slovenian Section

Chair:Joze MastnakRTV SlovenijaKolodvorska 2SI-1550 Ljubljana, SloveniaTel. +386 61 175 2133Fax +386 61 175 2130

Vice Chair:Dusan FeferUniversity of LjubljanaFaculty Electrical Engineering Trzaska 25SI-1000 Ljubljana, SloveniaTel. +386 61 176 8411Fax +386 61 126 4630E-mail [email protected]

Secretary:Tone SeliskarRTV SlovenijaKolodvorska 2SI-1550 Ljubljana, SloveniaTel. +386 61 175 2708Fax +386 61 175 2710E-mail [email protected]

Treasurer:Drago HribovsekRTV SlovenijaKolodvorska 2

SI-1550 Ljubljana, SloveniaTel. +386 61 175 3717Fax +386 61 175 3740

Committee:Joze GostisaSaso KranjcSavo Volovsek

SPAIN

Spanish Section

Chair:Antonio Pena GiménezE.T.S.E. TelecomunicaciónUniversidade de VigoES-36200 Vigo, Spain Tel. +34 98 681 21 30Fax +34 98 681 21 16E-mail [email protected]

Vice Chair/Treasurer:Luis I. Ortiz BerenguerDIACE.U.I.T. TelecomunicaciónUniversidad Politécnica de MadridCtra. Valencia Km.7ES-28031 Madrid, SpainTel. +34 91 336 78 26Fax +34 91 336 77 84E-mail [email protected]

Secretary:Juan Recio MorillasC/Florencia 14 3oDES-28850 Torrejon de Ardoz (Madrid)SpainTel. +34 91 540 14 03E-mail [email protected]

Committee:Eloi BatlleAlberto Duenas RodriguezRafael DuyosJose Javier Lopez MonfortJesus Ramallo Garcia

TURKEY

Turkish Section

Section Contact:Sorgun AkkorSTDGazeteciler Sitesi, Yazarlar Sok. 19/6Esentepe 80300 Istanbul, TurkeyTel. +90 212 2889825Fax +90 212 2889831E-mail [email protected]

Vice President:Mercedes OnoratoTalcahuano 141Buenos Aires, ArgentinaTel./Fax +5411 4 375 0116E-mail [email protected]

ARGENTINA

Argentina Section

Chair:Mercedes OnoratoTalcahuano 141 Buenos Aires, ArgentinaTel. +54 1 4375 0116E-mail [email protected]

Vice Chair:Andres MayoE-mail [email protected]

Secretary:German OlguinE-mail [email protected]

Committee:Eduardo BergalloAlberto CaglieroAlejandro BidondoCarlos Gauvron

BRAZILBrazil Section

Chair:Joel Vieira de BritoRua Cosme Velho 136/301ACosme Velho BR-22241-090 Rio de Janeiro, RJBrazilTel. +55 21 2556 8504E-mail [email protected]

Vice Chair:João Américo BezerraCentro Industrial de Aratu - DICAQuadra 6, lote 8 e 9BR-43780-000 Simões Filho, BA, BrazilTel. +55 71 394 1510, ext. 116Fax +55 71 394 1156E-mail [email protected]

Secretary:Rosalfonso BortoniRua Doutor Jesuíno Maciel, 1584/22Campo BeloSão Paulo, SP, Brazil 04615-004Tel.+55 11 5533-3970Fax +55 21 2421 0112E-mail [email protected]

Treasurer:Armando Vicente BaldassarraRua Guaicurus 300Vila Conceição, DiademaBR-09911-630 São Paulo, SPBrazilTel. +55 11 4048 2454Fax +55 11 4056 6964E-mail [email protected]

CHILE

Chile Section

Chair:Justo Andrés Concha AbarcaUniversidad Pérez Rosales

LATIN AMERICAN REGION


Brown Norte 290Ñuñoa, Santiago de ChileTel. +56 2 7571317Fax: +56 2 2238825E-mail: [email protected]

Vice Chair:Roberto Carlos Muñoz SotoUniversidad Pérez RosalesBrown Norte 290Ñuñoa, Santiago de ChileTel. +56 2 7571313Fax +56 2 2238825E-mail: [email protected]

Secretary/Contact:Andres SchmidtHernan Cortes 2768Ñuñoa, Santiago de ChileTel. +56 2 4249583E-mail [email protected]

Treasurer:Guillermo Grez MorandiUniversidad Pérez RosalesBrown Norte 290Ñuñoa, Santiago de ChileTel. +56 2 7571331Fax +56 2 2238825E-mail: [email protected]

COLOMBIA

Colombia Section

Chair:Mauricio CanoE-mail [email protected]

Vice Chair:Eduardo Narvaez

Secretary:Sandra Carolina HernandezCR 14 #87-25Bogotá, ColombiaTel./Fax +57 1 6297313E-mail [email protected]

Treasurer:Andres Londines

Committee:Juan Escobar AmadorHernan Dario Gutierrez

MEXICO

Mexico Section

Chair:Jose RevelesE-mail [email protected]

Vice Chair:Ricardo MantiniE-mail [email protected]

Secretary:Jorge UrbanoTel./Fax + 52 55 5240 1203E-mail [email protected]

Treasurer:Akinori TagoE-mail [email protected]

URUGUAY

Uruguay Section

Chair (Section Contact):Rafael AbalSondor S.A.Calle Rio Branco 1530C.P. UY-11100 Montevideo, UruguayTel. +598 2 901 26 70, +598 2 902 53 88Fax +598 2 902 52 72E-mail [email protected]

Vice Chair:Alvaro Espagnolo

Secretary:Alvaro Tuzman

Treasurer:Carlos Da Silveira

Committee:José FonteniaWilson GonzalezLuis LangoneDaniel Maggiolo

VENEZUELA

Taller de Arte Sonoro, Caracas Section(Student)

Chair:Felipe Alvarado

Vice Chair:David Antón

Secretary:Adolfo Hernández

Treasurer:Mario Basso

Committee:Eliana GonzálezCarlos Mata


Faculty Advisor:Carmen Bell-Smythe de LealAES Student SectionTaller de Arte SonoroAvenida Rio de JaneiroQta. Tres PinosChuao, VE-1061 Caracas, VenezuelaTel. +58 14 9292552Tel./Fax +58 2 9937296E-mail [email protected]

...

Venezuela Section

Chair (Section Contact):Elmar Leal

Avenida Rio de JaneiroQta. Tres PinosChuao, VE-1061 Caracas, VenezuelaTel. +58 14 9292552Tel./Fax +58 2 9937296E-mail [email protected]

Vice Chair:Juan FontAvenida Diego Cisneros, Ed. OficentroOf. 2E, Los RuicesCaracas VE-0171, VenezuelaTel. +58 2 351309Tel./Fax +58 2 352402

Secretary:Carmen Bell-Smythe de LealAvenida Rio de JaneiroQta. Tres PinosChuao, VE-1061 Caracas, VenezuelaTel. +58 14 9292552Tel./Fax +58 2 9937296E-mail [email protected]

Treasurer:Pierre JasparAvenida Rio de JaneiroQta. Tres PinosChuao, VE-1061 Caracas, VenezuelaTel. +58 14 9292552Tel./Fax +58 2 9937296

Committee:Manuel BetancourtAntonio González

Vice President:Neville Thiele10 Wycombe StreetEpping, NSW AU-2121, AustraliaTel. +61 2 9876 2407Fax +61 2 9876 2749E-mail [email protected]

AUSTRALIA

Adelaide Section

Chair:David MurphyKrix Loudspeakers14 Chapman RoadHackham AU-5163, South AustraliaTel. +618 8 8384 3433Fax +618 8 8384 3419E-mail [email protected]

Secretary:Ian TuckerVintage Sound17 Thornber StreetUnley AU-5061, South AustraliaTel. +618 8 8271 1360Fax +618 8 8272 6136E-mail [email protected]

Treasurer:Leigh Turner55 Mackinnon ParadeNorth Adelaide AU-5006, South AustraliaTel. +618 8 8367 0303

INTERNATIONAL REGION




Committee:Neville ClarkIan DurieuJohn GibsonJohn MathesonKeith TaylorAngelo Tullio

Mailing Address:AES Adelaide SectionP.O. Box 802Unley AU-5061, South Australia

...

Brisbane Section

Chair/Treasurer:David SpearrittOffice Tel. +61 7 3878 6133E-mail [email protected]

Secretary:David RingroseOffice Tel. +61 7 3364 6510E-mail [email protected]

Committee:Lynton GoughPeter PatrickDoug WattIan Wells

Mailing Address:AES Brisbane SectionP.O. Box 642Roma St. Post OfficeBrisbane, Queensland AU-4003, Australia

...

Melbourne Section

Chair:John Smyth22 Glen Ebor AvenueBlackburn, Victoria AU-3130, AustraliaTel. +61 3 9877 4273E-mail [email protected]

Secretary/Treasurer:Graham HaynesP.O. Box 5266Wantirna South, Victoria AU-3152AustraliaTel. +61 3 9887 3765Fax +61 3 9887 1688E-mail [email protected]

Committee:Rod BrownGreg Segal

...Sydney Section

Chair:David Hudson

Vice Chair:Fred Pickering

Secretary:Howard JonesTreasurer:Don Dowling

Committee:Kent LearnedAlistair Reynolds

Mailing Address:AES Sydney SectionP.O. Box 766Crows Nest, NSW AU-2065AustraliaTel. +61 2 9417 3200Fax +61 2 9417 3714E-mail [email protected]

HONG KONG

Hong Kong Section

Chair (Section Contact):Henry Ma Chi Fai HKAPA, School of Film and Television1 Gloucester RoadWanchai, Hong KongTel +852 2584 8824Fax +852 2588 1303E-mail [email protected]

Vice Chair:Zane Au On Kwok Shen Milsom & Wilke, Ltd. Suites 801-2, 8/F Two Chinachem Exchange Square338 King’s RoadNorth Point, Hong KongTel. +852 2850 0102Fax +852 2544 4266E-mail [email protected]

Secretary:Amornthep TantikovitDino Technology Limited, Room 1002Block A, Seaview Estate, 2 Watson RoadHong KongTel. +852 2648 6282Fax +852 2648 9382E-mail [email protected]

Treasurer:Chan Wei HimEastern Acoustic Development Limited Room 606TCL Tower, 8 Tai Chung RoadTsuen Wan, N.T., Hong KongTel. +852 2490 2121Fax +852 2728 2169E-mail [email protected]

Committee Consultant:Geoffrey Stitt

INDIA

India Section

Chair:Nandu Bhende

Insync StudiosT 3, Opp. Holy Cross Church Juhu Koliwada, JuhuMumbai 400 049, IndiaTel. +91 22 660 2618Fax +91 22 660 8144E-mail [email protected]

Vice Chair:Manohar Kunte Mumbai University Music DepartmentB Rd. ChurchgateMumbai 400 020, IndiaTel. +91 22 281 8995Fax +91 22 660 8144E-mail [email protected]

Secretary:Avinash OakAvisound A-20, DeepanjaliShahaji Raje MargVile Parle EastMumbai IN-400 057, IndiaTel. +91 22 26827535E-mail [email protected]

Treasurer:Uday ChitreEff Jumbo DarshanF-2/009 Western Exp. HighwayOpp. Goldspot FactoryAndheri East, Mumbai IN-400 069, IndiaE-mail [email protected]

Committee Members:Vinayak DeoKanwarjitsingh SawhneyMilind RaoraneDaman Sood

JAPAN

Japan Section

Chair:Hiroaki SuzukiVictor Company of Japan, Ltd./JVC3-12 Moriya-cho, Yokohama-shiKanagawa-ken 221-8528, JapanTel. +81 45 450 1779Fax +81 45 450 1780E-mail [email protected]

Vice Chair/Secretary:Akira Fukada NHK Program-Production

Engineering CenterJinnan 2-2-1, Shibuya-kuTokyo 150-8001, JapanTel. +81 3 5455 4781Fax +81 3 3481 1418

Treasurer: Hirokazu NakashimaTokyo Broadcasting System, Inc.5-3-6 Akasaka, Minato-kuTokyo 107-8006, JapanTel. +81 3 5571 2592Fax +81 3 5571 2145E-mail [email protected]


ORDERING INFORMATION

United States: Orders can be either prepaid in U.S. dollars drawn on a U.S. bank(please make checks payable to Audio Engineering Society) or prepaid by creditcard. Please complete order form and return to: Audio Engineering Society, 60 East42nd Street, Suite 2520, New York, NY 10165-2520. Tel: (212) 661-8528, Fax:(212) 682-0477. e-mail: [email protected]. Web site: www.aes.org. Prices: $15.00members; $20.00 nonmembers.United Kingdom: Orders must be prepaid in pounds sterling. Make chequespayable to Audio Engineering Society. Please complete order form and send to: AESBritish Section, P.O. Box 645, Slough, SL1 8BJ, United Kingdom. Tel: Burnham 44(0) 1628 663725, Fax: 44 (0) 1628 667002. e-mail: [email protected]. Prices: £9.38members; £12.50 nonmembers.Continental Europe: Do NOT send payment but indicate method of payment(credit card, Eurocheque, cheque in local currency or postal order) to: MichaelWilliams, Ile du Moulin, 62 bis de l’Artois, F 94170, Le Perreux sur Marne, France.Tel: 33 1 4881 4632, Fax: 33 1 4706 0648. e-mail: [email protected]. You will re-ceive a pro forma invoice in the required currency indicating details of payment.

Soft cover. Prices: $15.00 members; $20.00 nonmembers

Please send ______ copies of “Magnetic Recording: The Upsand Downs of a Pioneer” to:

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TTTThhhheeee MMMMeeeemmmmooooiiiirrrrssss ooooffff SSSSeeeemmmmiiii JJJJoooosssseeeepppphhhh BBBBeeeegggguuuunnnn

“...I was fortunate to have been involved in the development of magnetic recordingequipment as early as 1929, and I remained directly involved in this field until 1955.

This was a period when major technological advances were made and magneticrecording was thrust to the forefront of information storage techniques.

This book is a record of my experiences with magnetic recording....”—Semi Joseph Begun

Introduction

The engaging story of one of magnetic recording’s most respected pioneers begins in pre-World War IGermany, moves through the 1930s with the early development of the Lorenz steel tape machine, and on to theactivities at the United States’ Brush Development Company during World War II. A rare personal insight into

the emergence of a major audio technology by one of its most impressive contributors.

Assistant Treasurer: Katsuya Yamazaki

Auditors:Akira AsakuraYoshiharu Abe

Directors at Large:Shigeki KatohTadahiko NakaokiMasaki Sawaguchi

Directors of Operations:Masahiro FujimotoTakeo Yamamoto

Directors of Technical Meetings:Kazuo IshinoMasaru SakumaJun’ichi Yoshio

Directors of Membership:Katsuya GohToshio Kikuta

Directors of Liaison:Seiichi ChibaHiroyuki Ikeuchi

Directors of Public Relations:Kimio HamasakiToshiaki Setogawa

Directors of Engineering:Tohru KamekawaMasataka Nakahara

Advisors:Yoshizo SohmaAkihiko Takasu

Section Overseas Contact:Katsuya (Vic) Goh2-15-4 Tenjin-cho, Fujisawa-shiKanagawa-ken 252-0814, JapanTel./Fax +81 466 81 0681E-mail [email protected]

KOREA

Korea Section

Chair:Seong-Hoon KangTaejeon Health Science CollegeDepartment of Broadcasting Technology77-3 Gayang-dong Dong-guTaejeon, KoreaTel. +82 42 630 5990Fax +82 42 628 1423E-mail [email protected]

Vice Chair: Mun-Jae ChoE-mail [email protected]

Secretary:Won-Cheol LeeE-mail [email protected]

Treasurer:Hack-Yoon KimE-mail [email protected]

MALAYSIA

Malaysia Section

Section Contact:C. K. NgKing Musical Industries Sdn BhdLot 5, Jalan 13/2MY-46200 Kuala LumpurMalaysiaTel. +603 7956 1668Fax +603 7955 4926E-mail [email protected]

PHILIPPINES

Philippines Section

Chair (Section Contact):Dario (Dar) J. Quintos125 Regalia Park TowerP. Tuazon Blvd., CubaoQuezon City, PhilippinesTel./Fax +63 2 4211790, +63 2 4211784E-mail [email protected]

Vice Chair:Joselito (Mike) Pedero9 Gen. Delgado StreetSan Antonio VillagePasig City, Metro ManilaPhilippinesTel. +63 2 633 8710Fax +63 2 631 3277E-mail [email protected]

Secretary:Nicassius (Nicky) F. Cordero53 Mindanao AvenueQuezon City, Metro ManilaPhilippinesTel./Fax +63 2 821 8102E-mail [email protected]

Treasurer:Andrew Michael Sevilla22 Tacloban StreetAlabang Hills, Metro ManilaPhilippinesTel. +63 2 819 7372Fax +63 2 815 2177E-mail [email protected]

Committee:Martin GalanJose Francisco (Jiggs) HermanoCayetano Robert (Bobbit) JacintoArnedo (Dodie) C. Lucas

SINGAPORE

Singapore Section

Chair:Arthur Ngiamc/o Globe Precision Products Pte. Ltd.18 Jalan Masjid, #02-09Kembangan Plaza

Singapore 418944Tel. +65 6841 7700Fax +65 6841 3339E-mail [email protected]

Secretary:Kenneth J. Delbridge480B Upper East Coast Rd.Singapore 466518Tel. +65 9875 0877Fax +65 6220 0328E-mail [email protected]

Treasurer:Matthew PackerTel. +65 9362 2886E-mail [email protected]

Committee:Daniel LeeLi TeoRicht Teo

Honorary Auditors:Michael TehCedric Tio

Honorary Student Counselor:Roland Tan

Chair:Dell HarrisHampton University Section (AES)63 Litchfield CloseHampton, VA 23669Tel +1 757 265 1033E-mail [email protected]

Vice Chair:Scott CannonStanford University Section (AES)P.O. Box 15259Stanford, CA 94309Tel. +1 650 346 4556Fax +1 650 723 8468E-mail [email protected]

Chair:Isabella Biedermann European Student SectionAuerhahnweg 13A-9020 Klagenfurt, AustriaTel. +43 664 452 57 22E-mail [email protected]

Vice Chair:Felix Dreher European Student SectionUniversity of Music and Performing ArtsStreichergasse 3/1 AA-1030 Vienna, AustriaTel. +43 1 920 54 19E-mail [email protected]

EUROPE/INTERNATIONALREGIONS

NORTH/SOUTH AMERICAREGIONS

STUDENT DELEGATE ASSEMBLY



OF THE

SECTIONSWe appreciate the assistance of thesection secretaries in providing theinformation for the following reports.

NEWS


Boston SurroundedThe Boston Section held its annualbanquet on June 10 at the HendersonHouse in Weston, Massachusetts. After dinner 30 members and guestsenjoyed a talk by Tom Jung of DMPRecords on 5.1 surround sound andSACD.

Jung is a well-respected jazz pro-ducer and the principal of DMPRecords. DMP released its first jazzrecording in 1983, and in 1991 wasthe first to use 20-bit recording for acommercial release. In 1997, Jung began to use Sony’s DSD process forhigh resolution recording, releasingmore than eight albums in stereo for-mat on SACD before releasing thefirst multichannel SACD in 2000.

Jung began by talking about theevolution of the signal path over thelast 20-30 years. He commented onhow each section of the chain hasgrown and matured to allow for thepristine audio quality we take for

granted today. He also noted that high-resolution digital recording systemswould fail to benefit us without theconcurrent advances in microphonesand preamplifiers.

When it came to discussing the ben-efits of SACD, Jung largely let themusic do the talking. For his demon-stration, he used a Philips SACD1000 player with Meitner glass fibermultichannel DSD output, MeitnerDAC8 Mk IV DSD D to A converter,Meitner Switchman MK II multichan-nel monitor controller and Genelec1032A monitors in 5.1 surround. Heplayed music from Sacred Feast,Gaudeamus, So Real, Warren Bern-hardt, Gently, the Bob Mintzer BigBand, Grace, Broadway InspirationalVoices, “The Look of Love,” DianaKrall, Mahler and the San FranciscoSymphony. He also included a jazzrecording of “Light my Fire” by TheDoors and Patricia Barber as recordedby Jim Anderson, AES Eastern Region vice president. The music was

stunning and made a strongcase for both surroundrecording and multichannelSACD. The group thankedJung, Genelec and WillEgleston for their supportof this event.

Nelson Chadderdon

LA Tours UniversalSome 90 Los Angeles Sec-tion members gathered atUniversal Studio’s postpro-duction facility in UniversalCity, Hollywood, on July29. Host for the eveningwas David Goldstein, vicepresident for postproductionsound. Dave Turkow, a recent addition to the Uni-

versal staff, assisted him.The tour began with a visit to the

new Blue Wave facility, Universal’sDVD mastering and restoration opera-tion. The group got a look at one of themastering rooms as well as the centralmachine room and one of the restora-tion studios. Goldstein arranged for aviewing of a trailer for “A Cat in theHat,” an upcoming Christmas releasestarring Mike Myers. The film wasmixed in the Blue Wave’s Stage A.

Next, Goldstein and Turkow tookthe group through Universal’s latestdubbing theater, which was builtwhere the old scoring stage used to be.This new facility features a totally automated Harrison digital consoleand is equipped with the usual crea-ture comforts like ping pong tables,popcorn wagon, etc. The group alsovisited one of the other stages beingretrofitted with a Harrison digital con-sole. Also on the itinerary was the Foley stage, as well as one of the machine rooms that supports the dub-

Tom Jung tells Boston about 5.1 surround sound and SACD at the June meeting.

edit, color, synthesize and manipulatethe recorded performance.

Hearing LossOn February 20, 27 members of theChicago Section met again to hearGina Geissler speak on “The Mechan-ics of Hearing Loss: Impact on SoundPerception with Hearing Aids andCochlear Implants.” She began with areview of the pertinent anatomy andphysiology. She covered the construc-tion of the inner ear and the functionsof the inner and outer hair cells. Shealso talked about which portions of thecochlea pick-up corresponding partsof the audible spectra.

Geissler then discussed the way inwhich the human ear performs phaselocking for frequencies under 5000 Hzand, likewise, how the ear “fires” atany portion of a cycle for frequenciesabove 5 kHz. An increase in loudnessis represented in the cochlea as an increase in nerve firing rate along withmore cells firing. Geissler alsotouched on topics such as how hearingloss is measured, how to read an audiogram, sensorineural and conduc-tive hearing loss. She said the besttreatment for hearing loss is preven-tion; although she described severalapplications for hearing aids andcochlear implants that directly stimu-late the nerve fibers.

Geissler talked about some of theresearch currently being done in theareas of short electrode arrays for highfrequency use in conjunction withacoustic reinforcement for low fre-quencies, middle ear implantable hear-ing aids and experimental brain stemimplantable hearing aids.

Audio for GamesOn March 18, Martin Wilde, chair ofthe AES Technical Committee on Audio for Games, addressed 12 mem-bers of the section. He discussed recent trends in audio created specifi-cally for games. Wilde began by dis-cussing the resources available to early game systems that utilize 4- or8-bit sound chips with little to noRAM. These games either ran on slowgeneral-purpose computers or in afractured hardware market. Accordingto Wilde, the legacy of MIDI as it

According to Khan, the first approach can be seen as minimalist; i.e.,the attempt to create an aural documen-tation of the performance being record-ed. Khan showed how the “less ismore” theme is carried out with a verysimple audio system consisting of onlytransducers, amplification and routingor storage of the signal. No processingis used and only minimal microphones—typically the reference set as well asfocus or spot mics and an ambient microphone to support the image.

The second technique, based on per-formance, supersedes technical opti-mization. In this approach, transducerson both ends of the reproduction chainare recognized as the weak link in theaudio system. Instead of creating asnapshot of the performance, the engi-neer uses the characteristics of differ-ent transducers to create a sonic impression of what is being played.The goal is not to produce a perfectcopy of the musicians’ performancebut to convey the ideas of the perform-ers as an artist does in an impressionistpainting. Khan showed the sonic vari-ations that can be exploited during therecording process in areas such as polar pattern, diaphragm size vs.acoustical transduction tendencies andtransducer operation principles. Hesuggested which types of microphonesshould be used in different applica-tions and which microphones shouldnever be used in order to avoid dam-age to the transducer.

Khan discussed an electronics sys-tems approach whereby transducersare used with analog and digital cir-cuits and processors to intentionally

bing stage. This room containedeverything from a 2-in reel-to-reel to35-mm mag, multiple Pro Tools rigsand several Tascam MMR8 andMM16 machines—all the tools neededto support film dubbing today.

The tour’s highlight, however, wasa stop at the Hitchcock Theater, thelargest dubbing stage named after thegreat director who called Universalhome. Goldstein talked a bit about theroom and some of the projects com-pleted there, including The Italian Joband Gigli. To demonstrate, Goldsteinplayed a reel of The Mummy, whichfeatured a scene where the formerfriend of Pharaoh, who was buriedalive, arises from his long torment insomething of a foul mood. It was awe-some — and loud.

The group thanked Goldstein,Turkow and Sharon Chidos, whoarranged for lot passes for more than60 cars. To view more photos of thetour, visit: www.aes.org/sections/la/.

Morgan Martin

Chicago UpdateForty members of the Chicago Sec-tion met at Columbia College’s Audio Technology Center (ATC) onJanuary 16, to hear Gary Khan of thePegasus Recording Company talkabout the various approaches to clas-sic and modern audio recording. Inhis talk, Khan divided recording approaches into three categories: thepursuit of “sonic purity,” a perfor-mance-oriented approach, and anelectric systems perspective, and dis-cussed each one at length.

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In Los Angeles(from the left):Morgan Martin,David Goldstein,and DaveTurkow.

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precedence effect. Each channel mustcover the entire audience with 3-6 dBamplitude shading to counteract prece-dence, he said. He also noted the importance of uniform spectral bal-ance and uniform loudness of the direct sound, as well as minimizationof reverberant sound. Snow of BellLabs always said to add an extra chan-nel for each 25 feet of separation,which is about 22 ms.

Brown also talked about delayedcrossfeeds and mono delayed sourcesto cover the far sides of rooms. Hestated that an added mono delayedsource should arrive just after the LCRsignal and be at a level equal to sum ofthe LCR signals. He pointed out thatstereo is not a lot more costly thanmono reinforcement. The additionalcosts come primarily from increaseddesign complexity, a few good mixingdecks for L-C-R, more signal process-ing, more power amps and more loud-speaker locations.

Brown concluded by saying that engineers need to use different micro-phone techniques for larger rooms.Spaced microphones enhance the sys-tem and for large sources, one spacedmicrophone should be used per chan-nel. Coincident and near-coincidentstereo microphones do not work welldue to the minimal time difference between them. Brown pointed out thatone should not make the mix too wideand panning should be done only between adjacent channels.

Bob Zurek

Begault on ReverbAt the August meeting of the SanFrancisco Section Durand Begaultexpounded on moving late reverbera-tion, an acoustical characterization oflarge spaces such as concert halls andcathedrals. Some 40 people attended.Begault is a researcher at the SpatialAuditory Display Laboratory,NASA/Ames Research Center, Mof-fett Field, California.

Characterization of acoustic spacesby software programs is often based onthe assumption of uniform reflectivesurfaces, and linear reverberant decay.One flaw in this approach is that musicperformance sometimes happens in

nical Committees on Audio for Games,the Midi Manufacturers Association(MMA), the Interactive Audio SpecialInterest Group (IASIG), and the GameAudio Network Guild (GANG).

Systems for StereoOn May 6, Jim Brown of Audio Sys-tems Group spoke to over 40 membersof the Chicago Section on systems forstereophonic sound reinforcement.

Brown began by pointing out thatstereo in large rooms is very differentfrom stereo in small rooms. In addi-tion, two clusters of loudspeakers donot necessarily make stereo, andstereo does not necessarily mean twochannels, he said. Instead, stereo is related to the directivity of humanhearing, the difference between ears,time of arrival, and phase differencesas well as pinnae transforms.

“So why use stereo?” he asked theaudience. Stereo allows the acousticsumming of spaced microphonespicking up the same sound source. Hecontinued by stating that head direc-tivity makes the acoustic summingbetter than electrical summing;acoustic summing is much less severethan electrical summing due to thelack of comb filtering in air. Stereo insound reinforcement also provides asense of spaciousness, audience satis-faction at a 6-dB lower SPL, as wellas localization.

A demonstration using pink noiseand a small sound reinforcement system helped demonstrate comb fil-tering. Brown followed this up withdemonstrations of music in mono andstereo played back over a small rein-forcement system.

Brown then moved on to the differ-ences between large and small stereosystems, touching on topics such asthe effect of having many listenerseats versus only few, how arrivaltime differences dominate the largerdesigns, the importance of controllinglevel difference, and the benefits of visual source localization.

He then covered some important design criteria for stereo reinforce-ment systems, beginning with a dis-cussion of the work done at Bell Labsin 1936, showing that reinforcementsignal levels >10 dB can break the

was equated with “bad” music can betraced back to those days.

He then went on to discuss the chang-ing landscapes in both the PC and con-sole game arenas. Major breakthroughsin the PC market included the advent ofmultimedia extensions (1991) and device independent software abstraction(1995), which removed the task of writ-ing directly to the sound hardware. Oth-er important PC advances over the lastfew years had to do with increasedspeed of the machines and better soundhardware. The major points in the con-sole landscape he discussed were thestability of the hardware platforms, noneed to write to a subset of sound cards,and separate audio processors andmemory maps.

Wilde then moved on to a discus-sion of three-dimensional audio andthe three major console platforms onthe market today. He suggested thatproprietary solutions prevail. There isa definite need for industry-wide co-operation to maximize the end-userbenefit of the systems, he said. He alsotalked about the lack of consistentpractices for the production and repro-duction of games. That game manu-facturers are pressured to ship onmultiple platforms with differing audio capabilities leads to an econo-my-driven process, which is not goodfor the consumer.

Wilde said that the AES can helpplay a role in providing standardiza-tion and consistent implementation inthe audio mastering and playback environments so that the full potentialof gaming systems can be realized. Hementioned the markets of car/backseatgaming as well as wireless and mobile devices doubling as game plat-forms.

In terms of the outlook for the future, Wilde said that there is a mar-ketplace for skilled audio content andtechnology providers. There have beenadvances in this field in graphics andart training programs, but there is aneed for similar programs in the audiocommunity.

Before closing with a question-and-answer session, Wilde discussed thevarious industry alliances that are work-ing toward solutions of the aforemen-tioned problems, such as the AES Tech-

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and Sciences Section of Tempe,Arizona, attended a masteringclinic on May 14, hosted by MattMurman. Murman describedmastering as the final step in thecreative process for making analbum into a stereo mix. Thetime frame for this process isusually about one day. The intentof mastering is to maximize theemotional impact while main-taining the cohesiveness of thecollection. In mastering, the engi-neer also strives to eliminate anyunwanted noise such as hiss,clicks and vocal pops. The main

tools used in mastering are equaliza-tion, compression and fades. Murmanalso discussed the history of master-ing, the differences in mastering con-soles, and some of the common “dos”and “don’ts” to help engineersachieve the right mix.

Studio TourOn August 25, members of the PennState Student Section drove toBethlehem, PA, for a tour of AngelMountain’s new studio recording facilities. Mike Horvath, director ofsales and marketing, began the tour inthe media suite where the productionstaff combines audio, video, andgraphics for advertising spots andcorporate videos.

The tour continued through a Pro-

complex, irregularly shaped places.Such places may have several rooms,known as “coupled” spaces, withacoustic energy feeding back and forth.In large, coupled spaces, several rever-berant decays can happen at the sametime. Time delays are long enough thatthe listener may hear spatially separatedreverberant decays, known as “movingreverb.” An example is the sensation ofspatially shifting reverberation, after an organ note is stopped. The effect can beimpressive.

Begault conducted a series of mea-surements at Grace Cathedral, a Goth-ic style church in San Francisco,known for its pleasing acoustics. Heused seven laboratory microphones,distributed through the church. Pistolshots from five locations provided excitation. The results of Begault’stests were clear from looking at graphsand listening to reproductions. Rever-berant decay had considerable nonlin-earity, both in time and amplitude.Moving reverb happens in GraceCathedral, and presumably in othercoupled spaces. Standard, automatedreverb measurements do not give information about nonlinear decay.Such measurements average severaldecays into one.

Begault’s innovative work inacoustic measurements may well setnew standards for characterizing large,complex spaces.

Paul Howard

Mastering ClinicThirty-four student members of theConservatory of Recording Arts

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Durand Begault expounds on moving latereverberation at San Francisco meeting.

Tools edit suite and on to the maincontrol room for recording and mix-ing. An engineer and producer whowere remixing an album in 5.1 byrap/hip-hop artist Ludacris chattedwith members and played back a songfor us. We also saw the main studiospace, which can accommodate a 40-piece orchestra, and the THX mix the-ater. If you missed the tour, check outwww.pilchner-schoustal.com/am/ forphotographs and more information.

Alexandra Loubeau

DTS in South IndiaH. Sridhar, media artist, spoke to theSouth India Section about the DTSaudio technique on August 9. Twenty-five people attended the meeting atModi Digital Audio Pvt. Ltd in Myla-pore, Chennai.

Sridhar explained the need to

educate the public on the wide spec-trum of sound possible with 5.1 audio.He told the group that creating it isquite an experience. The mixing taskwas quite challenging, which requiredhim to spend months on research. Hedid, however, enjoy the challenge. He emphasized the need to work in a mostresponsible manner, and stated the importance of encouraging people.The group appreciated his patiencewhile telling them about technical aspects of the final products.

H. Sridhar spoke to members of the South India Section on DTS audio in August.

A E S S U S T A I N I N G M E M B E R

DSD PROCESSOR and interfacemodule for the ADA-8 converter andprocessor unit provides a multichannelA/D and D/A conversion path for orig-ination and playback of DSD record-ings. The unit also supports high-quali-ty conversion between PCM and DSDformats. The DSD capability allowsexisting and new ADA-8 users to takeadvantage of the developing market forSACD production and mastering. ThePCM-DSD conversion capability isuseful for those working on SACDprojects with existing PCM equipment.Prism Media Products Inc., 21 PineStreet, Rockaway, NJ 07866, USA; tel.+1 973 983 9577; fax +1 973 9839588; e-mail [email protected];Web site www.prismsound.com.


WIDE-DISPERSION CEILINGLOUDSPEAKERS feature installer-friendly features such as fast-mountbrackets, built-in back-cans, and frontbaffle transformer taps. The new F-Series includes the F-122CU, a 5-infull-range loudspeaker with a specialdiffuser for wide off-axis high frequen-cy coverage and full UL1480 andUL2043 listing for fire protective andgeneral purpose signaling. The F-2852C is a 6.5-in coaxial ceiling loud-speaker ideal for higher power applica-tions requiring extended bass response.Other models include the F-2352C 5-incoaxial ceiling unit; the F-2322C 5-infull-range ceiling loudspeaker; and forlower power applications, the F-2352SC 5-in coaxial and ultra compactF-1522SC 4-in coaxial. All of the new

F-Series models are backed by a five-year warranty. TOA Electronics, Inc.,601 Gateway Boulevard, Suite 300,South San Francisco, CA 94080, USA;tel. +1 650 588 2438 or 800 733 7088(toll free); fax +1 650 588 3349; Website www.toaelectronics.com.

OPTICAL TRANSCEIVERS forGigabit Ethernet or Fibre Channel appli-cations are now available. The new D21Series of Small Form Factor (SFF)transceivers are IEEE 802.3z, and ANSIX3.297 compliant and stackable. Theproducts use multi-die hybrid technolo-gy to integrate a dual optical transceiverinto a package featuring an industry-standard, MSA-compliant 2 x 10 foot-print. The units have industry-standardLC interfaces and a package height ofonly 0.75-in The D21 Series will enableOEM customers to design networkequipment with doubled port density,while maintaining the traditional levelsof performance and reliability requiredfor gigabit ethernet and fibre channelsystems. Stratos Lightwave, Inc., 7444W. Wilson Avenue, Chicago, IL, USA; tel. +1 708 867 9600; fax +1 708867 4140; e-mail [email protected]; Web site www.stratoslight-wave.com.

LINEAR FADER PACK provides ten100-mm linear faders to add to the S100eight-channel mixer. The S120 providesfader control and mutes on each channelas well as the main left-right masters.Simply connect into the inserts of theS100 or any console or rack piece withinserts. The unit features +500 dB head-

AND

DEVELOPMENTSProduct information is provided as aservice to our readers. Contact manu-facturers directly for additional infor-mation and please refer to the Journalof the Audio Engineering Society.

NEW PRODUCTS


CONFERENCES, MEETINGS…

MEDIA-TECH Expo 2004, a premierconference of the media manufacturingindustry, will be held May 25-27,2004, in Hall 3.0 at the Messe Frank-furt Centre in Frankfurt, Germany. Every area of the media industry willbe represented, from raw materials,production equipment and manufactur-ing technology to packaging and ser-vices. A grand exhibition in Hall 3.0,which was designed by renowned architect Sir Nicholas Grimshaw, nowserves as one of the world’s most mod-ern show halls. This backdrop will provide an impressive and suitablyhigh-tech venue for the gathering ofthe media industry.

The following product groups willbe included in the exhibition and program: CD/DVD manufacturing,polycarbonate dryers, polycarbonatestorage/feeding systems, CD/DVDreplication lines, CD/DVD printingand packaging, offline test equipmentfor CD/DVD, CD/DVD players/burn-ers/writing equipment, premastering,audio/video tape cassette manufactur-ing, consulting services, serviceproviders plastic materials forCD/DVD manufacturing, software, recycling equipment, floppy disc andhard disc manufacturing, licensing,media supplies/replicators, fulfillment,Web delivery, encoding, digital rightsmanagement, data storage, alternativeremovable media, facility managementand licensing financing.

For questions regarding booth reser-vations, call: Barbara Kaelberer, tel:49-0-611-95166-18 or ChristineHirschle, tel: 49-0-611-95166-38. Forall other information, contact: MesseFrankfurt Ausstellungen GmbH,Taunusstr. 7a, 65183 Wiesbaden, Ger-many; tel: 49-0-611-95166-18/38, fax:49-0-611-95166-23, e-mail: [email protected],Internet: www.media-tech.net. In theUnited States: Mediatech Association,5200 Willson Road, Suite 140, Edina,MN 55424, USA; tel: 952-836-2737,fax: 952-836-2730, or e-mail:

[email protected].

TRACK

SOUND

room and a theoretical minimum noisefloor. The fader pack fits into a 19-inrack mounting space. Trident Audio, 9Arkwright Rd., Colnbrook, Slough,Berks., SL3 0HJ, UK; tel. +44 1753689345; fax +44 1753 687182; orTrident Audio, c/o John Oram, OramPro Audio; tel. +44 1474 815 300; fax+44 1474 815 400; [email protected]; Web sitewww.oram.co.uk.

MONITORING SYSTEM allows theuser to both monitor and analyze digitaltransport streams. The R&S DVM 100base unit allows simultaneous controlof two, three or four transport streamsat data rates of up to 216 Mbit/s. Theaddition of the DVM 120 makes it pos-sible to set up a scalable monitoringsystem with a maximum of 20 transportstream inputs. As the instruments areonly one unit in height, network opera-tors and playout centers can conve-niently monitor a large number oftransport streams in real time and withminimum space requirements. The system is ideal for (satellite, cable, ter-restrial) network operators, operators ofplayout centers, system integrators, andsurveillance government authorities.Rohde & Schwarz GMbH & Co. KG,Mühldorfstr. 15, D-81671 Munich,Germany; tel. +49 89 4129 13779; fax:+49 89 4129 13777; e-mail [email protected]; Website www.rohde-schwarz.com.

PLANNING SYSTEM SOFTWAREPACKAGE predicts the effects ofsound insulation in buildings. For agiven construction or combination ofconstructions, Bastian 2.1 softwarewill indicate insulation effectiveness inone-third octave bands or single num-ber ratings like Rw, STC, IIC, andOITL. It handles airborne and impactnoise from interior spaces and airbornenoise from the environment. The soft-

ware meets European standards EN-12345-1, -2, -3. Results are shown perASTM E-413, E-989, and ISO 717. Ithas a database that includes 1500 con-struction elements. In addition, otherconstructions can be added. An option-al auralization package provides 46interior and exterior sounds and ninedifferent receiving room types. Thisallows the user to assess how much theconstruction will attenuate sounds. Theoption uses a PC running WindowsXP, 2000, 9x, etc. Scantek, Inc., 7060-L Oakland Mills Road, Columbia, MD 21046, USA; tel. +1 410 2907726; fax +1 410 290 9167; e-mail [email protected]; Web sitewww.scantekinc.com.


CONSOLE is designed for live soundtouring, fixed installation, and broad-cast applications. The Sy80 features abrand new control surface, XFAD(patent pending) software, and a faderconfiguration system that allows usersto define the function of any fader onthe console. There are 80 inputs, 80outputs, and 80 faders, as well as 48mix buses housed in a new chassisweighing less than 176 pounds. Theconsole operates with real-time con-sole software manager, Sensoft 8, anda new DSP module built around thelatest SHARC digital signal proces-sors. The console also incorporatesMix Box, a local audio rack that isremote-controlled from the control sur-face. To handle the rigors of touring,the Sy80 features dual redundant auto-switching power supplies that may befitted in the back of the console or in arack. The optional stage box allowsremote placement and control ofmicrophone or line inputs and outputson stage, close to the input sources.The stage box also serves as an activesplitter and can feed up to three con-soles through coaxial or optional fiberoptic cables. Innova SON, Zone duKenyah, F-56400 Plougoumelen,Brittany, France; tel +33 297 24 3434; fax +33 297 24 34 30; [email protected]; distributed bySennheiser Electronic Corporation, 1Enterprise Drive, Old Lyme, CT06371, USA; tel. +1 860 434 9190; fax+1 860 434 1759; Web sitewww.sennheiserusa.com.


AND

NEW PRODUCTS

DEVELOPMENTS

2004 March 17-19: SpringMeeting of the AcousticalSociety of Japan, Atsugi,Japan. Fax: +81 3 52561022. On the Web:www.soc.nii.ac.jp/asj.

•2004 April 17-22: NAB 2004,

Las Vegas Convention Cen-ter & Las Vegas Hilton, LasVegas, Nevada, USA. For in-formation tel: 800-342-2460or 202 595-2052.

•2004 May 8-11: 116th AES

Convention, Messe Berlin,Berlin, Germany. Contact: e-mail: [email protected] page 1120 for details.

•2004 May 17-21: International

Conference on Acoustics,Speech, and Signal Processing ( ICASSP 2004), Montreal, Canada.On the Web: www.-

icassp2004.com).

•2004 May 24-28: 75th An-

niversary Meeting (147thMeeting of the AcousticalSociety of America, NewYork, NY, USA, tel: 516-576-2360; fax: 516-576-2377; e-mail: [email protected].

•2004 June 17-19: 25th Inter-

national Conference, Lon-don, UK, "Metadata for Audio." For information con-tact John Grant, chair, e-mail: [email protected].

•2004 October 28-31: 117th

AES Convention, MosconeCenter, San Francisco, CA,USA.

Upcoming Meetings

A digital studio cable guide is a16-page, full-color bulletin written tohelp designers, specifiers and installers of cabling systems for theA/V, broadcast and entertainmentmarket sort through the challengesposed by the digital revolution. Thebulletin discusses the future of digitaltransmission, installation issues andthe value of Installable Performance™— Belden’s assurance that its cableswill deliver the specific performanceeven after the rigors of installation.

Detailed product specifications andtransmission distance charts are pro-vided for a wide range of Brillianceproducts, including AES/EBU DigitalAudio Cables, Precision Video Cable(analog and digital), VideoFLEX®Snake Cables (analog and digital), andAudio and Video Composite CameraCables. For a free copy of the DigitalStudio Cable Guide, contact: BeldenElectronics Division, P.O. Box 1980,Richmond, IN 47375, USA; tel: 1-800-BELDEN-4, fax: 765-983-5294,Internet: www.belden.com.

Methode Electronics, Inc. has announced a new Interconnect Prod-ucts Catalog in CD-ROM format andon the Methode Web site: seewww.methode.com. The catalog com-bines products sold by Methode Con-nector Products, Methode Far East(Singapore), Duel Systems and prod-ucts previously sold by Methode underthe Adam Tech name into a singlecomprehensive product offering. It also incorporates a number of new productsincluding USB, IEEE1394, Serial ATAand PCMCIA frame kit product linesamong others. Products are organized

by type and series to help readers navi-gate more easily. A hard copy catalogis available this fall (2003).

IN BRIEF AND OF INTEREST…

Game Audio Programming, by JamesBoer is a comprehensive guide to interactive audio programming for theMicrosoft Windows® platform. Writ-ten for C++ programmers implement-ing an audio system for an entertain-ment or multimedia title, this referencecovers a wide range of topics includingDirectX Audio, audio decompressionlibraries, hardware filters and effects,geometric representation of world datafor effects, occlusion and obstructionand more. In addition, a full-featured,documented and internally commentedgame audio programming (GAP) library is referenced throughout thebook to explain various concepts.

The library is included on the com-panion CD-ROM and can be used aseither a ready-to-use library for gamesor as reference code to help implementan audio system. Also on the CD-ROM is the GAP sample librarysource, samples and reference docu-mentation; a Disk 2 demo, courtesy ofDolby; Ogg Vorbis SDK and an encoder for wave file conversions,from Ogg Vorbis; Sensaura’s SDKwith sample code, programs, libraries,etc., from Sensaura; and a demo of aprogram for formatting C/C++ in awide variety of styles, provided bySourceStylerC++. Price is: $59.95,Canada: $92.95. Charles River Media,20 Downer Avenue, Suite 3, Hing-ham, MA 02043, USA; tel: 781-740-0400, e-mail: [email protected].

LITERATUREThe opinions expressed are those ofthe individual reviewers and are notnecessarily endorsed by the Editors ofthe Journal.

AVAILABLE

CATALOGS, BROCHURES…

A new master catalog in CD-ROMformat represents more than 3000 wireand cable products for the networking,broadcast, broadband, industrial, resi-dential, sound, security, and alarmmarkets. The Master Catalog CD-ROM is a collection of Adobe AcrobatPortable Document Files (PDFs)linked together with a bookmark sys-tem. The opening interface, or menu,offers the various cable sections, alongwith two easy-to-use reference guides.The first guide, the Part Number In-dex, allows the user to find any partnumber contained in the catalog. Thesecond guide, the Cable Finder, helpsthe user locate cables based upon theirconstruction using AWG size, type ofshielding and number of conductors asselection criteria. A technical informa-tion section is also available, whichcontains information on cable con-struction, color-coding, packaging andindustry standards. In addition, theelectronic catalog gives the user theoption of viewing and downloadingthe catalog in its entirety, by section,subsection or individual page.

The CD-ROM is designed to auto-run in either Windows® or MAC plat-forms and includes a link to the AdobeAcrobat Web site where the user candownload the latest version of AcrobatReader. The entire contents of the CDcan be copied to a hard drive whilestill allowing full functionality. To receive a copy of the catalog, contact:Belden Electronics Division, P.O. Box1980, Richmond, IN 47375, USA; tel:1-800-BELDEN-4, fax: 765-983-5294, Internet: www.belden.com.



Section symbols are: Aachen Student Section (AA), Adelaide (ADE), Alberta (AB), All-Russian State Institute of Cinematography(ARSIC), American River College (ARC), American University (AMU), Argentina (RA), Atlanta (AT), Austrian (AU), Ball StateUniversity (BSU), Belarus (BLS), Belgian (BEL), Belmont University (BU), Berklee College of Music (BCM), Berlin Student(BNS), Bosnia-Herzegovina (BA), Boston (BOS), Brazil (BZ), Brigham Young University (BYU), Brisbane (BRI), British (BR),Bulgarian (BG), Cal Poly San Luis Obispo State University (CPSLO), California State University–Chico (CSU), Carnegie MellonUniversity (CMU), Central German (CG), Central Indiana (CI), Chicago (CH), Chile (RCH), Citrus College (CTC), CogswellPolytechnical College (CPC), Colombia (COL), Colorado (CO), Columbia College (CC), Conservatoire de Paris Student (CPS),Conservatory of Recording Arts and Sciences (CRAS), Croatian (HR), Croatian Student (HRS), Czech (CR), Czech RepublicStudent (CRS), Danish (DA), Danish Student (DAS), Darmstadt (DMS), Denver/Student (DEN/S), Detmold Student (DS), Detroit(DET), District of Columbia (DC), Duquesne University (DU), Düsseldorf (DF), Expression Center for New Media (ECNM),Finnish (FIN), Fredonia (FRE), French (FR), Full Sail Real World Education (FS), Graz (GZ), Greek (GR), Hampton University(HPTU), Hong Kong (HK), Hungarian (HU), Ilmenau (IM), India (IND), Institute of Audio Research (IAR), Israel (IS), Italian(IT), Italian Student (ITS), Japan (JA), Kansas City (KC), Korea (RK), Lithuanian (LT), Long Beach/Student (LB/S), Los Angeles(LA), Louis Lumière (LL), Malaysia (MY), McGill University (MGU), Melbourne (MEL), Mexican (MEX), MichiganTechnological University (MTU), Middle Tennessee State University (MTSU), Moscow (MOS), Music Tech (MT), Nashville (NA),Netherlands (NE), Netherlands Student (NES), New Orleans (NO), New York (NY), North German (NG), Northeast CommunityCollege (NCC), Norwegian (NOR), Ohio University (OU), Pacific Northwest (PNW), Peabody Institute of Johns HopkinsUniversity (PI), Pennsylvania State University (PSU), Philadelphia (PHIL), Philippines (RP), Polish (POL), Portland (POR),Portugal (PT), Ridgewater College, Hutchinson Campus (RC), Romanian (ROM), Russian Academy of Music, Moscow (RAM/S),SAE Nashville (SAENA), St. Louis (STL), St. Petersburg (STP), St. Petersburg Student (STPS), San Diego (SD), San Diego StateUniversity (SDSU), San Francisco (SF), San Francisco State University (SFU), Serbia and Montenegro (SAM), Singapore (SGP),Slovakian Republic (SR), Slovenian (SL), South German (SG), Southwest Texas State University (STSU), Spanish (SPA), StanfordUniversity (SU), Swedish (SWE), Swiss (SWI), Sydney (SYD), Taller de Arte Sonoro, Caracas (TAS), Technical University ofGdansk (TUG), The Art Institute of Seattle (TAIS), Toronto (TOR), Turkey (TR), Ukrainian (UKR), University of Arkansas at PineBluff (UAPB), University of Cincinnati (UC), University of Hartford (UH), University of Illinois at Urbana-Champaign (UIUC),University of Luleå-Piteå (ULP), University of Massachusetts–Lowell (UL), University of Miami (UOM), University of NorthCarolina at Asheville (UNCA), University of Southern California (USC), Upper Midwest (UMW), Uruguay (ROU), Utah (UT),Vancouver (BC), Vancouver Student (BCS), Venezuela (VEN), Vienna (VI), West Michigan (WM), William Paterson University(WPU), Worcester Polytechnic Institute (WPI), Wroclaw University of Technology (WUT).

INFORMATION

MEMBERSHIP

Shu Sum ToMIT, Dept. Rm. B322, 20 Tsing Yi Rd.,Tsing Yi Island, Hong Kong (HK)

Nil UnerdemDolby Laboratories, 100 Potrero Ave., SanFrancisco, CA 94103 (SF)

Almer J. van den BergGeldropseweg 181, NL 5613 LM,Eindhoven, Netherlands (NE)

Laurens van der WerffLihgestraat 38, NL 6541 WH, Nijmegen,Netherlands (NE)

Andre van SchaikSchool of Electrical and InformationEnginering, University of Sydney, NSW2006, New South Wales, Australia (SYD)

Sander J. van WyngaardenTNO Human Factors, P. O. Box 23, NL 3769ZG, Soesterberg, Netherlands (NE)

Kelvin VarstSonionkirk A/S, Fuglevangsvej 45, DK 8700,Horsens, Denmark (DA)

Josif VezzloiMura di Porta Galliera 13, IT 40126,Bologna, Italy (IT)Michael C. Volkerding946 Redway Ave., Cincinnati, OH 45229(DET)Clarence Wai Kuen Lui12D Knight Court, 38 Shing Tai Rd., ChaiWan, Hong Kong (HK)Thomas WisdomDolby Laboratories Inc., 100 Potrero Ave.,San Francisco, CA 94103 (SF)

Ara Smith1635 Mississippi St. NE, Fridley, MN 55432(UMW)Torben Sonderskov45 Dunfield Ave. PH21, Toronto, M4S 2H4,Ontario, Canada (TOR)Jacob S. SorensenElverhojen 19c, DK 2730, Herlev, Denmark(DA)Gabriele J. A. G. SpecialeCivitas Studios, Strandholms alle’ 30, DK2650, Hvidovre, Denmark (DA)

Jason Stark4 Sunrise Circle, Holmdel, NJ 07733 (NY)

Chris Straley212 W. Van Buren, Chicago, IL 60607 (CH)

Bruno Strapko1932 N. 74th Ave., Elmwood Park, IL 60707(CH)

Gregg Stutchman421 Walnut St. #120, Napa, CA 94559 (SF)

David SutedjaJi. Kelapa Puyuh 3 lok KD-14, KelapaGading Permai, Jakarta, DKI-Jaya 14240,Indonesia

Leif SveeHananbakken 22, NO 1529, Moss, Norway(NO)

Charles Swiger578 Henry St. #1, Brooklyn, NY 11231 (NY)

Derek Tallent5 Jasmin Close, The Rock, Telford,Shropshire, TF3 5RJ, UK (BR)

King TamDspfactory Ltd., 611 Kumpf Dr. Unit 200,Waterloo, N2V 1K8, Ontario, Canada (TOR)

ASSOCIATES

MEMBERS

These listings represent new membership according to grade.

Thomas W. Taylor2302 Jonathans Landing, Richmond, TX77469

Marc Teixidor SerraCircumval. Iacio Puig Colomer 86, ES17820, Banyoles, Spain (SPA)

Anthony Tew19 Carr Ln., Acomb, York, YO26 5HT, UK(BR)

Andy ThompsonAdrian James Acoustics Ltd., 65 YarmouthRd., Blofield, Norwich, Norfolk, NR13 4LG,UK (BR)

Russell ThomsonUnit 2 87 Ford St., Ivanhoe, AU- 3079,Victoria, Australia (MEL)

Robert Thornburg9850 Lombardy Ave., Bloomington, CA92316 (LA)

Dan Thorton649 Dr. Johns Rd., Screven, GA 31590 (AT)

Olaf TitelNassauische Str. 54, DE 10717, Berlin,Germany

Dejan Z. TodorovicJ. Prodanovic 1/11, YU 11400, Mladenovac,Yugoslavia (SAM)

Roland TsuiTelevision Broadcast Ltd., TVB City, 77Chun Choi St., Tseunf Kwan O IndustrialEstate, Kowloon, Hong Kong (HK)

Jerry Tubb5446 Hwy. 290 West #270, Austin, TX 78735

Alexander V. UsovKorablestroiteley Str. 35, #987, RU 199397,St Petersburg, Russia (STP)

Rachel Uwa1123 N. Spaulding, Chicago, IL 60651 (CH)

Jan-Maarten van den BoomCornelis de Wittlaan 53, NL 2582 AC, DenHaag, Netherlands (NE)

Rene van DijkJakob Israel de Haanstraat 8, NL 9745 DK,Groningen, Netherlands (NE)

Hans van DongenJP Coenstraat 11 bis, NL 3531 EK, Utrecht,Netherlands (NE)

F. A. van LeeuwenLaan van Vredestein 45, NL 2552 DT, DenHaag, Netherlands (NE)

Corne van PuijenbroekZekeringstraat 40, NL 1014 BT, Amsterdam, Netherlands (NE)

Sergey P. VelichkoLenina Str. 62-10, Tumen Region, RU629602, Muravlenko, Russia (STP)

Luca Vialvia di Oratoio 102, IT 56015, Oratoio (PI),Italy (IT)

Matthias von Saint-GeorgeAm Steinweg 22, DE 76327, Pfinztal,Germany

Timothy WalkerLondon College of Music & Media, TVUMedia Block, Ealing Film Studios, EalingGreen, London, W5 5EP, UK (BR)Daniel Walton2801 N. Gravenstein Way, Sebastopol, CA95472 (SF)Rhys D. WebbP. O. Box 164, Kellyville, NSW 2155, NewSouth Wales, Australia (SYD)Steve WeeBlk. 166 Tampines St. 12 #04-325, 52116Singapore (SGP)Barak Weinstein119 Haight St. #10, San Francisco, CA 94102(SF)Richard Welly4279 C Monroe Dr., Boulder, CO 80303 (CO)Stuart WhitbyMediaco-The Presentation Company, 179 W.6th Ave., Vancouver, V5Y 1K3, BritishColumbia, Canada (BC)Mark S. Willsher4754 17th St., San Francisco, CA 94117 (SF)Ethan Winer34 Cedar Vale Dr., New Milford, CT 06776(BOS)Daire WinstonBeech View, Newtown, Rathcoole, Dublin24, IrelandRichard A. Wollrich12587 Henzie Place, Granada Hills, CA91344 (LA)Lias Woodward464 Eureka St., San Francisco, CA 94114(SF)Mateusz WozniakPSPaduioware.com s.c., Dzikiej Rozy 11/8,Jozefoslaw, PL 05-500, Piaseczno, Poland(POL)Yuh-Tong Yen3F #90 Ho-Fong 2nd Rd., Hsintien, Taipei231, Republic of China, TaiwanEric J. YpeyUtrechtseweg 36-8, NL 1213 TV, Hilversum,Netherlands (NE)Jee In Yu502# 923-11 Mock 1-dong, Yangchoon-ku,Seoul 158-051, Korea (RK)Yury V. ZakutayloCentrainaya Str. 28, #22, RU 684090,Viluchinsk, Russia (STP)Sergey P. ZamushinskiyShkolnaya Str 1 #5, Nadmskiy Region, RU629759, Long-Ugan, Russia (STP)Greg Zastoupil3734 Ashford Dunwoody Rd. #S, Atlanta,GA 30319 (AT)Tao ZhangStarkey Labs, Inc., 6600 Washington Ave. S.,Eden Prairie, MN 55344 (UMW)Erich ZwyssigWolfson Microelectronics plc, 20 BernardTerrace, Edinburgh, EH8 9NX, UK (BR)


MEMBERSHIP

INFORMATION

AdvertiserInternetDirectoryBSWA Technology Co. Ltd. ............1113www.bswa-tech.com

General Motors ................................1113www.gm.com/careers

Human Factors and Ergonomics Society.................................................................1083 www.hfes.org

*Prism Media Products, Inc. ..............859 www.prismsound.com

Rockford...........................................1112www.rockford.com

*SRS Labs. Inc. ...................................851www.srslabs.com

*THAT Corporation ...........................1071www.thatcorp.com

*AES Sustaining Member.

Rockford Corporation, a leading internation-al manufacturer of high performance audiocomponents and top brands such as Rock-ford Fosgate, MB Quart, Q-Logic, OmniFi,and Hafler, is seeking an exceptional, ca-reer-minded Senior Designer to research,d e s i g n a n d d e v e l o p p o w e r a m p l i f i e r s .Unique opportunity to serve as analog ex-pert on cross-functional teams and enjoy theincredible freedom to create innovative am-pl i f i cat ion technology for the company’sgrowing line of professional, home and mo-bi le products. Must have extended boardlevel experience from concept to productcompletion; the creativity and imaginationto steer technology leaps; strong leadershipand mentoring capabilities; excellent com-munication and people ski l ls; and a stylethat is proactive, influential, collaborative,and thrives in an unstructured, fun, fast,and future-focused environment. BSEE re-quired, advanced degree preferred; packageincludes competitive base salary, bonus eli-gibility, outstanding benefits and relocationassistance. For information email to [email protected] or fax to 602-604-9045.

SENIOR POWERAMPLIFIER DESIGNER

MEMBERSHIP

INFORMATION

Jennifer A. GibsonArts Insitute Centre for Digital Image andSound, 3261 Beta Ave., Burnaby, V5G 4K4,British Columbia, Canada

Remy Galichet119 rue Manin, FR 75019, Paris, France(CPS)

John R. Gall700 S. 4th Lot 4, Battle Creek, NE 68715(NCC)

Donnie Gamsjager385 Middle Rd. Tpke., Woodbury, CT 06798(IAR)

Perrine Ganjean33 rue des Vinaigriers, FR 75010, Paris,France (CPS)

Per GanteliusAnkarskatavagen 79C, SE 941 34, Pitea,Sweden (ULP)

Robert Gatley3810 Sutton Place Blvd. #1211, Winter Park,FL 32792 (FS)

Mateny Geffrard3300 University Blvd., Winter Park, FL32792 (FS)

Reuben Ghose1575 Summerhill Ave. #109, Montreal, H3H1C5, Quebec, Canada (MGU)

John Gillian1249 Richmond Ln., Wilmette, IL 60094(UIUC)

Jaspaer A. Goforth2602 West 22nd, North Platte, NE 69101(NCC)

Tami Goldfadim617 5th Ave. W. #3A, Seattle, WA 98119(TAIS)

Guillermo Gonzalez602 Trinidad Ct., Winter Park, FL 32792 (FS)

Magdalena GrabowskrMeer en Vaart 412, NL 1068 LH,Amsterdam, Netherlands (NES)

Carissa L. Gragg8037 Tucker Way, Sacramento, CA 95828(ARC)

Mark R. Gramann830 S. Pugh St. #1, State College, PA 16801(PSU)

Hugh Griffiths2 Glasgow St., Glasgow, G12 8JN, Scotland

Daniel Guilliaume13057 30th Ave. NE, Seattle, WA 98125(TAIS)

Pierre Guynot de BoismenuCollao del Hornillo 3, Portal A-4A, ES28035, Madrid, Spain

Anders HaggblomAnkarskatavagen 77A, SE 941 34, Pitea,Sweden (ULP)

Chris Hahn2341 State St. #3, Salem, OR 97301

Rodolfo R. Hamilton13 Marty Circle, Roseville, CA 95678 (ARC)Carl H. HanssonFru Alstad Granhem, SE 231 96, Trelleborg,Sweden (ULP)Andrew Harper12648 W. 6th Pl., Lakewood, CO 80401(DEN/S)William Harris2111 Bonsallo Ave., Los Angeles, CA 90007(USC)Joel Hawbaker324 Park St., Bensenville, IL 60106 (CC)Adam Hawk222 S. Figueroa St. #822, Los Angeles CA90012 (USC)Peter HeddelinAnkarskatavagen 80 C, SE 94164, Pitea,Sweden (ULP)Jason P. Hedges5-685 Wonderland Rd. South, London, N6K1M1Ontario, Canada Jason Heffel28 Beaumont, San Francisco, CA 94132(USF)Gabe Herbert600 Black Lake Blvd. SW #177, Olympia,WA 98502 (TAIS)Adrianto Hermawi3771 S. McClintock Ave. Ste. 4112D, LosAngeles, CA 90007 (USC)Andrew Heroy1015 W. 275 North, Angola, IN 46703 (CC)Julian Herring6739 El Colegio Rd. #205, Goleta, CA 93117(USC)William J. Higgins1015 W. 34th St. #1501, Los Angeles, CA90007 (USC)Matthew Hill83 King Alfred St., Derby, DE22 3QL, UKMark A. Hillebrandt1749 Eaton Rd. #67, Chico, CA 95973 (CSU)Aaron C. Hoerner121 Sourdough Ct., Folsom, CA 95630(ARC)Shawn C. Hoerner121 Sourdough Ct., Folsom, CA 95630(ARC)Paul Hohberg5101 Stratford Circle, La Palma, CA 90623(USF)John J. Holbrook801E. Benjamin Ave., P. O. Box 226, D121,Norfolk, NE 68701 (NCC)Erica Holmstrom1710 S. Gilbert Rd. #1189, Mesa, AZ 85204(CRAS)Andrew Holt15 Dobbin Close, Cloughfold, Rossendale,Lancashire, BB4 7TH, UKErin Horan45 N. Salisbury St. #11, West Lafayette, IN47906 (BSU)

STUDENTS


OnStar is the increasingly popular in-vehicle safety, security and informationservice from General Motors. We offerthe latest advanced technologies, cut-ting-edge careers, and the chance to work with a recognized leader in the f ield. Give your career a newvoice–check out the following challengingopportunities available at our facility inTroy, Michigan.

Pro jec t Engineer , Vo iceRecogni t ion

Work within the Voice Technology CoreTeam in support of developing and im-proving speech recognition delivered ser-vices to the OnStar subscriber. A BSEE orequivalent training is required, and directexperience in voice recognition systems(both Network and Client based) usingboth imbedded and portable phones.This is a full- or part-time position.

Cel lu lar Hands Free/AudioEngineer

Work with suppliers in developing andimproving hands free and voice recog-nition audio processing hardware.

Requirements include a BSEE or equiva-lent training, with a minimum of 5 years’experience in Hands Free wireless perfor-mance of both digital and analog systems.

For detailed career descriptions andto submit your resume via our Web site,visit: www.gm.com/careers. EOE

Find Your Voice at OnStar

MEMBERSHIP

INFORMATION

Lumir HrmaKonviktska 7, CZ 110 00, Prague 1, CzechRepublic (CRS)

Paul Hudson2106 Bouquet Ct. #208, Orlando, FL 32807(FS)

Edwin M. HuitsGrote Loef 69, NL 6581 JE, Malen,Netherlands (NES)

Mihael IlicStubicka 48a, HR 10000, Zagreb, Croatia(HRS)

Ivan B. IlicMededa Useinovica 47, YU 19210, Bor,Yugoslavia

Nenad IljadicaMihe Klaica 19, HR 22000, Sibenik, Croatia(HRS)

Ricardo Isais8634 Chinchilla, El Paso, TX 79907

Nicholas Ito22610 S. #103, Torrance, CA 90501 (LB/S)

Tim Jackson13C Bramall Ct., Cannon St., Salford, M36WB, UK

Adam Jackson78 10th St. E. #903, St. Paul, MN 55101(MT)

Roy Jackson430 162nd St. #117, South Holland, IL 60473(CC)

Henrik JakobssonAnkarskatavagen 81 A, SE 941 28, Pitea,Sweden (ULP)

Christopher W. JanssenNorthwestern College, 363 Snelling Ave. N.,Saint Paul, MN 55113

Christopher Jennings25010 Bell Mountain, San Antonio, TX78255

Kristopher Jensen2708 S. Melrose, Tacoma, WA 98405 (TAIS)

Jenique Johnson26 Throop Ave. 2A, Brooklyn, NY 11206(IAR)

Eric Johnson15232 Foothill Blvd. #108, Sylmar, CA91355 (CTC)

Bojan JovanovicSjenjak 37, HR 31000, Osijek, Croatia (HRS)

Dave Kaduk812 Brookside Dr., Bartlett, IL 60103 (CC)

Maths KaellqvistAnkarskatavagen 83 C, SE 941 34, Pitea,Sweden (ULP)

Benedikt-Lars KaiserGriestai 46, AT 8020, Graz, Austria (GZ)

Andrew Kantos508 5th St. N., Sartell, MN 56377 (TAIS)

Tarek Karaman6 Pound Ln., Marlow, Buckinghamshire, SL72AQ, UK

Howard Kearey10-42 Grandview Grove, Praham, Vic 3181,Victoria, Australia

Nicole Keller211 Lenora St. #609, Seattle, WA 98121(TAIS)

Justin D. Kelly5525 Saulsbury Ct., Arvada, CO 80002(DEN/S)

Colin Kennedy7509 Benelux Ct., Plano, TX 75025

Anthony Kilmartin211 Lenora St. #609, Seattle, WA 98121(TAIS)

Joonwan Kim702 Tatom St., Huntsville, AL 35805

Eugene KimDartmouth College, 1673 Hinman, Hanover,NH 03755

Tracy Kindler8409 Palmaire Way, Orangeville, CA 95662(ARC)

Omar Kinghorn6508 Cypress St., Vancouver, V6P 5L6,British Columbia, Canada (BCS)

Justin Knievel202 S. 8th Apt. B, Norfolk, NE 68701 (NCC)

Robert Kodadek22 Sussex St., Roxbury Crossing, MA 02120(UL)

Edwin Koerperick517 E. Fairchild St. #5, Iowa City, IA 52245

Andrew Kovarik105 S. Fourth St. #101, Champaign, IL 61820(UIUC)

Aaron K. Krasnick16 Sawmill Rd., Acton, MA 01720 (WPI)

Florian A. KrebsSchonaugasse 111, AT 8010, Graz, Austria(GZ)

Josef Kumka321 5th Ave. NE, Minneapolis, MN 55413(MT)

David Lamb38 Boul. de Reims, Lorraine, J6Z 2Y5,Quebec, Canada (MGU)

Fabian Rafael A. LandazabalAv. Centenario #488 A-201, Col. MercedGomez, Del. Alvaro Obregon, Mexico City,DF 01600, Mexico

Philippe P. Larock2601 E. McKellips Rd. #2056, Mesa, AZ85213 (CRAS)

Ben Larson3223 64th SW, Seattle, WA 98116 (TAIS)

Marko LasicGajeva 5, HR 10000, Zagreb, Croatia (HRS)

Christina LeitnerZimmersplatzgasse 1/3/10, AT 8010, Graz,Austria (GZ)

Daniel LeopoldPraestgaardsgatan 77 C, SE 941 37, Pitea,Sweden (ULP)

Johnson W. LeRoy2545 Fulton Ave. #44, Sacramento, CA95821 (ARC)

Perry Lewis2014 S. 1st St., Norfolk, NE 68701 (NCC)

Brad Libby1365 Monroe Dr. #B7, Atlanta, GA 30324

Betty Lin20776 E. Walnut Canyon Rd., Walnut, CA91789 (USC)

Jesper LindellParonvagen 11, SE 262 65, Angelholm,Sweden (ULP)

Alexis Ling11 rue d’Hautpoul, FR 75019, Paris, France(CPS)

Nicolas LitwinPlaza Violeta Parra 3 - 2nd B, ES 28529,Rivas Vaciamadrid, Spain

Ivan S. LopatinPushkin, Detskoselski bulvar 9, #116, RU189620, St Petersburg, Russia (STPS)

Milan LovricBiankinijeva 9, HR 10000, Zagreb, Croatia(HRS)

Matthew S. Lucas9027 Brydon Way, Sacramento, CA 95026(ARC)

Johannes LuigGlacisstr. 65, AT 8010, Graz, Austria (GZ)

John Lukas2005 Emerson Ave. S., Minneapolis, MN55405 (MT)

Jarrod Lynn1002 S. Lincon Ave., Urbana, IL 61801(UIUC)

Jont O. LyttensAnkarskatavagen 89 A, SE 941 34, Pitea,Sweden (ULP)

Sam Macy563 Navaho Trail Dr., Franklin Lakes, NJ07417 (IAR)

Daniel Maksym62 Plymouth Ave., Mount Sinai, NY 11766(IAR)

Richard Mansfield2300 E. Broadway Rd., Tempe, AZ 85282(CRAS)

Frank MarekHorsengade 11 St., DK 8000, Arhus C,Denmark (DAS)

Adam Martin160 Alamo Ranch Rd., Alamo, CA 94507(USC)

Jeffrey Martinez3865 Parfet St., Wheat Ridge, CO 80033(DEN/S)


ANTHOLOGY SERIES

Collected papers fromthe AES’s internationalconferences are reprint-ed here from the authors'original manuscripts.Books are bound indurable paper covers andare shrinkwrapped.

Proceedings of the AES 24th Interna-tional Conference: Multichannel Audio, The New Reality, Banff, Alber-ta, Canada, 2003 June 26-28.This conference was a follow-up to the19th Conference on surround sound.These papers describe multichannelsound from production and engineer-ing to research and development,

manufacturing, and marketing.350 pages

Also available on CD-ROM

Proceedings of the AES 23rd Interna-tional Conference: Signal Processingin Audio Recording and Reproduc-tion, Copenhagen, Denmark, 2003May 23-25.These 22 papers focus on sound record-ing and reproduction from microphone toloudspeaker, including the interaction between loudspeaker and room.

291 pagesAlso available on CD-ROM

Proceedings of the AES 22nd Inter-national Conference: Virtual, Syn-

thetic, and Entertainment Audio, Espoo, Finland, 2002 June 15-17. These 45 papers deal with virtual andaugmented reality, sound synthesis, 3-Daudio technologies, audio coding tech-niques, physical modeling, subjectiveand objective evaluation, and more.


Proceedings of the AES 21st Interna-tional Conference: ArchitecturalAcoustics and Sound Reinforcement,St. Petersburg, Russia, 2002, June 1-3.These 59 papers cover the entirespectrum of this important topic.


The AES's renowned seriesof collected papers ofarchival quality are repro-duced exactly as they ap-peared in the Journal andother authoritative sources.These books measure 81⁄4inches (209.6 mm) by 111⁄2inches (285.8 mm), are

bound in durable paper covers, andare shrinkwrapped for safe shipment.

Disk Recording Vol.1: Groove Geom-etry and the Recording Process edit-ed by Stephen F. Temmer. These papers describe the major contributionsto the art of disk recording in the areasof groove geometry, cutterheads andlathes, styli and lacquers, pressings,and high-density disk technology.

550 pages

Disk Recording Vol. 2: Disk Playbackand Testing edited by Stephen F. Tem-mer. Written by experts, these papersdiscuss the subjects of disk playback,disk pickups, tone arms and turntables,and quality control.

550 pages

Loudspeakers Vol.1 edited by Ray-mond E. Cooke. These papers (from1953 to 1977) were wr itten by the

world's greatest transducer expertsand inventors on the design, construc-tion, and operation of loudspeakers.

448 pages

Loudspeakers Vol. 2 edited by Ray-mond E. Cooke. Papers from 1978 to1983 cover loudspeaker technology, extending the work initiated in Vol. 1.

464 pages

Loudspeakers Vol. 3: Systems andCrossover Networks edited by Mark R.Gander. These papers with commentsand corrections were published from1984 through 1991 in the area of loud-speaker technology. With a companionvolume on transducers, measurementand evaluation, the publication extendsthe work of the first two volumes. An ex-tensive list of related reading is included.

456 pages

Loudspeakers Vol. 4: Transducers,Measurement and Evaluation edited by Mark R. Gander. Papers withcomments and corrections explore thissubcategory from 1984 through 1991. Abibliography lists essential titles in thefield. 496 pages

Sound Reinforcement edited by DavidL. Klepper. These papers deal with the

significant aspects of the development ofsound-reinforcement technology and itspractical application to sound system de-sign and installation. 339 pages

Sound Reinforcement Vol. 2 edited byDavid L. Klepper. These papers withcomments and corrections were originallypublished between 1967 and 1996. In ad-dition to extending the work of the firstanthology on this vital topic, Volume 2adds earlier papers now considered sem-inal in the original development of thetechnology. 496 pages

Stereophonic Techniques edited byJohn M. Eargle. These articles and doc-uments discuss the history, develop-ment, and applications of stereophonictechniques for studio technology, broad-casting, and consumer use.

390 pages

Time Delay Spectrometry edited byJohn R. Prohs. Articles of Richard C.Heyser’s works on measurement, analy-sis, and perception are reprinted from thepages of the JAES and other publica-tions, including Audio magazine andIREE Australia. A memorial to the author’s work, it contains fundamentalmaterial for future developments in audio.

280 pages

continued

papers, and conference papers published by the AES between1953 and 2002. Almost 10,000 papers and articles are stored inPDF format, preserving the original

documents to the highest fidelitypossible, while also permitting full-text and field searching. The librarycan be viewed on Windows, Mac,and UNIX platforms.

This 19-disk elec-tronic librarycontains mostof the Journal

articles, convention

ELECTRONIC LIBRARY (Updated through 2002)

AESSPECIALPUBLICATIONS

PROCEEDINGS

Proceedings of the AES 20th Interna-tional Conference: Archiving, Restora-tion, and New Methods of Recording,Budapest, Hungary, 2001 October 5-7.This conference assessed the latest developments in the fields of carrierdegradation, preservation measures, digi-tization strategies, restoration, and newperspectives in recording technology.


Proceedings of the AES 19th Interna-tional Conference: SurroundSound—Techniques, Technology,and Perception, Schloss Elmau, Germany, 2001 June 21-24.The emphasis of the conference was onsurround sound for mainstream recordingand broadcasting applications, accordingto the so-called "5.1" or 3/2-stereo stan-dard specified in ITU-R BS.775.


Proceedings of the AES 18th Interna-tional Conference: Audio for Informa-tion Appliances, Burlingame, Califor-nia, 2001 March 16-18.This conference looked at the new breedof devices, called information appliances,created by the convergence of consumerelectronics, computing, and communica-tions that are changing the way audio iscreated, distributed, and rendered.

Available on CD-ROM only

Proceedings of the AES 17th Interna-tional Conference: High-Quality Audio Coding, Florence, Italy, 1999September 2-5.The introduction of new, high-capacity media, such as DVD and the Super Audio CD, along with the latest develop-ments in digital signal processing, IC de-sign, and digital distribution of audiohave led to the widespread utilization ofhigh-quality sound. These new technolo-gies are discussed. 352 pages


Proceedings of the AES 16th Inter-national Conference: Spatial SoundReproduction, Rovaniemi, Finland,1999 April 10–12.Var ious aspects of spat ial sound reproduction (perception, signal pro-cessing, loudspeaker and headphonereproduction, and applications) arecovered in this volume. 560 pages


Proceedings of the AES 15th Internation-al Conference: Audio, Acoustics & SmallSpaces, Copenhagen, Denmark, 1998October 31–November 2.Reproduction of sound in small spaces,such as cabins of automobiles, trucks,and airplanes; listening and controlrooms; and domestic rooms is ad-dressed in detail in the papers included.

219 pages

Proceedings of the AES 13th Interna-tional Conference: Computer-Con-trolled Sound Systems, Dallas, Texas,1994 December 1–4.A complete collection of the papers pre-sented at this conference covers all aspects of computer-controlled sound

systems including product design, imple-mentation and real-world applications.

372 pages

Proceedings of the AES 12th Inter-national Conference: Perception ofReproduced Sound, Copenhagen,Denmark, 1993 June 28–30.Papers by experts in the science of human perception and the applicationof psychoacoustics to the audio indus-try explore the performance of low bit-rate codecs, multichannel sound sys-tems, and the relationships betweensound and picture. 253 pages

Proceedings of the 11th Internation-al AES Conference: Audio Test &Measurement, Portland, Oregon,1992 May 29–31.These papers describe both the engi-neering and production aspects of test-ing including state-of-the-art techniques.Authors examine electronic, digital, andacoustical measurements, bridging thegap between subjective and objectivemeasurement to advance the science ofaudio measurement. 359 pages

Proceedings of the 10th Internation-al AES Conference: Images of Audio,London, UK, 1991 September 7–9.Papers cover recording and postpro-duction, digital audio bit-rate reduction,digital audio signal processing and au-dio for high definition television plus a100-page tutorial on digital audio.` 282 pages

Proceedings of the AES 9th Interna-tional Conference: Television SoundToday and Tomorrow, Detroit, Michi-gan, 1991 February 1-2.These fully illustrated papers explore thelatest in audio and video technologies.

256 pages

Proceedings of the AES 8th Interna-tional Conference: The Sound of Audio,Washington,D.C., 1990 May 3-6.These papers are devoted to theprogress of sound, including perception,measurement, recording and reproduc-tion. The book is fully illustrated.

384 pages

Proceedings of the AES 7th In-ternational Conference: Audio inDigital Times, Toronto, Ontario,Canada, 1989 May 14-17.Written by experts in the field of digitalaudio, these papers explore digital audio from the history, basics, hard-ware, and software to the ins and outs.It is a valuable guide to practitionersand students not only for the presentbut also as an important historicalrecord. 384 pages

Proceedings of the AES 6th Interna-tional Conference: Sound Reinforce-ment, Nashville, Tennessee, 1988May 5-8.These papers were written by engineersand the savants of sound reinforcement.They cover the history of sound rein-forcement, new frontiers in applications,computers, new concepts, electronic architecture, and sound reinforcement inthe future. 600 pages

AES UK Conferences

Proceedings of the AES UK Confer-ence: Audio Delivery, London, UK,2002 April 15-16.Papers look at the advances beingmade in the delivery of high-speed audio to homes. 122 pages

Proceedings of the AES UK Confer-ence: Silicon for Audio, London, UK,2001 April 9-10.Papers keep audio equipment designersup-to-date on advances in silicon, andhelp silicon designers understand theequipment engineers want. 128 pages

Proceedings of the AES UK Confer-ence: Moving Audio, Pro-Audio Net-working and Transfer, London, UK,2000 May 8-9.These papers describe how the capacityand speed of new computer systemsand networks bring flexibility, conve-nience, and utility to professional audio.

134 pages

Proceedings of the AES UK Confer-ence: Audio—The Second Century,London, UK, 1999 June 7-8.These papers written by experts coverthe benefits and challenges introducedby the convergence of the computer andaudio industries.. 176 pages

Proceedings of the AES UK Conference:Microphones and Loudspeakers:The Ins and Outs of Audio, London,UK, 1998 March 16–17. These papers update the transducer spe-cialist and nonspecialist with the latest inmicrophone and loudspeaker develop-ment, exploring the influence on equip-ment and working practices. 135 pages

Proceedings of the AES UK Confer-ence: The Measure of Audio (MOA),London, UK, 1997 April 28–29.Audio test and measurement is beingrevolutionized by advancing technology.Learn about the various aspects of thisimportant topic from papers written byprofessionals in the field. 167 pages

Proceedings of the AES ANM UK Con-ference: Audio for New Media, Lon-don, UK, 1996 March 25–26.The papers in this valuable book are avital reference for those involved in thetechnologies. 117 pages

Proceedings of the AES DAB UK Con-ference: The Future of Radio, London,UK, 1995 May 2–3.These papers provide cutting-edge information on digital audio broadcast-ing and a review of competing digitalradio services. 143 pages

Proceedings of the AES UK Confer-ence: Managing the Bit Budget, (MBB)London, UK, 1994 May 16–17.The boundaries of digital audio have extended in different directions in termsof bit rate and sound quality. These papers address the complex aspects ofdigital analog conversion, signal process-ing, dynamic range, low bit-rate coding,and performance assessment.

189 pages

continued

Collected Papers on Digi-tal Audio Bit-rate Reduc-tion, edited by NeilGilchrist and ChristerGrewin.The emerging technologyof reducing the bit rate ofdigital signals is amply cov-ered in this important

publication. Pertinent topics and authors—all experts in their fields—were

Auditory Illusions andAudio, Vol. 31, No. 9.Edited by Diana Deutsch.The 1983 September issueof the Journal, devoted to paradoxes in human audio perception, explores

auditory illusions from varied view-points (with two demonstration Sound-sheets)

Digitization of Audio: A Comprehen-s ive Examinat ion of Theory , Implementa t ion , and CurrentPractice, Vol. 26, No. 10.

JOURNAL ISSUES

ALSO AVAILABLE

The 1978 October issue of the Jour-nal features the internationally refer-enced tutor ia l paper by Barr y A.Blesser on analog-to-digital conver-sion. Implementation questions arealso examined.

Shields and Grounds: Safety, PowerMains, Studio, Cable and Equipment,(special excerpt).The June 1995 issue of the Journal wasa definitive and comprehensive collec-tion of information on this important top-ic. The seven papers by Neil Muncyand other experts in the field have been

P e r c e p t u a l A u d i oCoders: What to ListenFor. This is the first edu-cational/tutorial CD-ROMpresented by the AES

Technical Council on a particular topic,combining background information withspecific audio examples. To facilitatethe use of high quality home playbackequipment for the reproduction of audioexcerpts, the disk can also be playedback on all standard audio CD players.

Perceptual audio coding combines ele-ments from digital signal processing,coding theory, and psychoacoustics.The Audio Engineering Society Pre-sents Graham Blyth in Concert: ACD of seven selected pieces fromGraham Blyth’s recitals performed onsome of the great pipe organs.Membership pin: A gold-colored lapelpin with AES logo in blue and white. Membership certificate: A personalized

membership certificate suitable for fram-ing measures 81⁄2 inches by 11 inches.Please print your name exactly as youwould like it to appear on the certificate.

VIDEO CASSETTES:“An Afternoon with Jack Mullin” is a 1⁄2-inch VHS and PAL format cassette tapecapturing the growth of entertainmenttechnology. “A Chronology of American TapeRecording ” (VHS format)

reprinted into a convenient guide for designers and practitioners. 82 pages

Commemorative Issue... The AES:50 Years of Contributions to AudioEngineering, Vol. 46, No. 1/2. Assembled by John J. Bubbers, guesteditor, 1998 January/February.This special issue covers the founding,development and internationalizationof the society. It includes an impres-sive group of review papers on the es-sential technologies in the audio field.It is an indispensable addition to anyaudio library. 134 pages

able on one CD-ROM. Individual CD-ROMs are available for the 105th to114th conventions. Contact Andy Velozat Headquarters [email protected].

Internet: For preprint lists, prices andsearch engines see the AES Web site.

Andy Veloz at AES [email protected].

CD-ROMs: Preprints presented at the103rd Convention in New York (1997September) and the 104th Convention(Amsterdam, 1998 May 16-19) are avail-

Printed Form: Many of the papers pre-sented at AES conventions are preprint-ed and available individually in printedform. For preprint lists, prices and order-ing see the AES Web site or contact

CONVENTION PREPRINTS

AES STANDARDS AND INFORMATION DOCUMENTS

Standards may be obtained by clicking on “Standards in print” at www.aes.org/standards/.

Free Downloading of StandardsSingle copies of AES Standards in PDF form may be downloaded free from the AESSC Web page. Because the AESSCreserves the right to make changes in these documents, the latest printing must be downloaded before each use.These are copyrighted documents that must not be printed or circulated except in part where useful in standards bodydeliberations or with written permission of the AES Standards Committee. Any use of AES Standards information obtained from this Web site in a republishing or selling activity is expressly prohibited.

carefully selected by the editors. The 16reviewed and edited manuscripts are pre-sented here for the first time. It is an essential reference for understanding thecurrent and future technology of audiocodecs. 208 pages

Magnetic Recording: The Ups andDowns of a Pioneer—The Memoirsof SemI Joseph Begun, edited byMark Clark. 168 pages

A History of Audio Engineering andMagnetic Recording Before 1943. The collection of individual preprintspresented in the session on AudioHistory at the AES 94th Convention,Ber l i n , Ger many, 1993 March , describes work in Germany and theU.S. beginning in 1876. The spe-c ia l ly pr iced co l lec t ion inc ludesprepr ints 3481 through 3488 and3521 through 3523. PDF only

SPECIAL PUBLICATIONS

Proceedings of the AES DAI UK Confer-ence: Digital Audio Interchange, (DAI)London, UK, 1993 May 18–19.Since audio is part of a multimedia envi-ronment, there are more questions relat-ed to the effective exchange of digital

audio signals between equipment. Thesepapers explore them. 135 pages

Proceedings of the AES DSP UK Confer-ence: Digital Signal Processing, London,UK, 1992 September 14–15.

Papers cover issues crucial to the appli-cation of DSP in domestic and profes-sional audio including processor choice,filter design and topology, code develop-ment, psychoacoustic considerations,and applications. 239 pages

continued

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____Disk Recording, Vol. 1 $ 30.00 $ 40.00 _____ ____Disk Recording, Vol. 2 30.00 40.00 _____ ____Loudspeakers, Vol. 1 30.00 40.00 _____ ____Loudspeakers, Vol. 2 30.00 40.00 _____ ____Sound Reinforcement 30.00 40.00 _____ ____Stereophonic Techniques 30.00 40.00 _____ ____Time Delay Spectrometry 30.00 40.00 _____

ORDERS OF 2 OR MORE (ANY COMBINATION OF THE ABOVE), PER VOLUME 27.00 37.00 _____

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continued

United Kingdom: Orders must be prepaid in pounds sterling. Contact the U.K. office for prices. Send completed order form to:

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____ANM UK Conference, 1996 28.00 40.00 _____ ____MOA UK Conference, 1997 28.00 40.00 _____ ____MAL UK Conference, 1998 28.00 40.00 _____ ____ASC UK Conference, 1999 28.00 40.00 _____ ____Moving Audio UK Conference, 2000 28.00 40.00 _____ ____Silicon for Audio, UK Conference, 2001 28.00 40.00 _____ ____Audio Delivery, UK Conference, 2002 28.00 40.00 _____

ORDERS OF 2 OR MORE (ANY COMBINATION OF THE ABOVE), PER VOLUME 26.00 36.00 _____ ____16th International Conference 40.00 60.00 _____ ____16th CD-ROM 40.00 60.00 _____ ____17th International Conference 40.00 60.00 _____ ____17th CD-ROM 40.00 60.00 _____ ____18th CD-ROM only 40.00 60.00 _____ ____19th International Conference 40.00 60.00 _____ ____19th CD-ROM 40.00 60.00 _____ ____20th International Conference 40.00 60.00 ____ ____20th CD-ROM 40.00 60.00 _____ ____21st International Conference 40.00 60.00 _____ ____21st CD-ROM 40.00 60.00 _____ ____22nd International Conference 40.00 60.00 _____ ____22nd CD-ROM 40.00 60.00 _____ ____23rd International Conference 40.00 60.00 _____ ____23rd CD-ROM 40.00 60.00 _____ ____24th International Conference 40.00 60.00 _____ ____24th CD-ROM 40.00 60.00 _____

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Before 1943 (historical papers) in PDF only

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AES CONVENTIONS AND CON11th Regional ConventionTokyo, JapanDate: 2003 July 7–9Location: Science Museum,Chiyoda, Tokyo, Japan

The latest details on the following events are posted on the AES Website: http://www.aes.org

Convention chair:Kimio HamasakiNHK Science & TechnicalResearch LaboratoriesTelephone: +81 3 5494 3208Fax: +81 3 5494 3219Email: [email protected]

Convention vice chair: Hiroaki SuzukiVictor Company of Japan (JVC)Telephone: +81 45 450 1779

Email: [email protected]

Papers chair: Shinji KoyanoPioneer CorporationTelephone: +81 49 279 2627Fax: +81 49 279 1513Email:[email protected]

Workshops chair: Toru KamekawaTokyo National University of FineArt & Music

117th ConventionSan Francisco, CA, USADate: 2004 October 28–31Location: Moscone CenterSan Francisco, CA, USA

Papers cochair:Ben BernfeldKrozinger Str. 22DE-79219 Staufen, GermanyEmail: [email protected]

Papers cochair:Stephan PeusGeorg Neumann GmbHEmail: [email protected]

Convention chair:Reinhard O. SahrEickhopskamp 3DE-30938 Burgwedel, GermanyTelephone: + 49 5139 4978Fax: + 49 5139 5977Email: [email protected]

Vice chair:Jörg KnotheDeutschlandRadioEmail: [email protected]

116th ConventionBerlin, GermanyDate: 2004 May 8–11Location: Messe BerlinBerlin, Germany

Papers cochair:Gerhard StollIRT, Munich, GermanyEmail: [email protected]

Papers cochair:Russell MasonUniversity of Surrey, Guildford, UKEmail: [email protected]

Conference chair:John GrantNine Tiles Networks, Cambridge, UKEmail: [email protected]

25th International ConferenceLondon, UK“Metadata for Audio”Date: 2004 June 17–19

117th

2004

San Francisco

New York

2003

Convention chair:Zoe ThrallThe Hit Factory421 West 54th StreetNew York, NY 10019, USATelephone: + 1 212 664 1000Fax: + 1 212 307 6129Email: [email protected]

Papers chair:James D. JohnstonMicrosoft CorporationTelephone: + 1 425 703 6380Email: [email protected]

115th ConventionNew York, NY, USADate: 2003 October 10–13Location: Jacob K. JavitsConvention Center, New York,New York, USA

2004Berlin, Germany

FERENCESPresentationManuscripts submitted should betypewritten on one side of ISO size A4(210 x 297 mm) or 216-mm x 280-mm(8.5-inch x 11-inch) paper with 40-mm(1.5-inch) margins. All copies includingabstract, text, references, figure captions,and tables should be double-spaced.Pages should be numbered consecutively.Authors should submit an original plustwo copies of text and illustrations.ReviewManuscripts are reviewed anonymouslyby members of the review board. After thereviewers’ analysis and recommendationto the editors, the author is advised ofeither acceptance or rejection. On thebasis of the reviewers’ comments, theeditor may request that the author makecertain revisions which will allow thepaper to be accepted for publication.ContentTechnical articles should be informativeand well organized. They should citeoriginal work or review previous work,giving proper credit. Results of actualexperiments or research should beincluded. The Journal cannot acceptunsubstantiated or commercial statements.OrganizationAn informative and self-containedabstract of about 60 words must beprovided. The manuscript should developthe main point, beginning with anintroduction and ending with a summaryor conclusion. Illustrations must haveinformative captions and must be referredto in the text.

References should be cited numerically inbrackets in order of appearance in thetext. Footnotes should be avoided, whenpossible, by making parentheticalremarks in the text.

Mathematical symbols, abbreviations,acronyms, etc., which may not be familiarto readers must be spelled out or definedthe first time they are cited in the text.

Subheads are appropriate and should beinserted where necessary. Paragraphdivision numbers should be of the form 0(only for introduction), 1, 1.1, 1.1.1, 2, 2.1,2.1.1, etc.

References should be typed on amanuscript page at the end of the text inorder of appearance. References toperiodicals should include the authors’names, title of article, periodical title,volume, page numbers, year and monthof publication. Book references shouldcontain the names of the authors, title ofbook, edition (if other than first), nameand location of publisher, publication year,and page numbers. References to AESconvention preprints should be replacedwith Journal publication citations if thepreprint has been published.IllustrationsFigure captions should be typed on aseparate sheet following the references.Captions should be concise. All figures

should be labeled with author’s name andfigure number.Photographs should be black and white prints without a halftone screen,preferably 200 mm x 250 mm (8 inch by10 inch).Line drawings (graphs or sketches) can beoriginal drawings on white paper, or high-quality photographic reproductions.The size of illustrations when printed in theJournal is usually 82 mm (3.25 inches)wide, although 170 mm (6.75 inches) widecan be used if required. Letters on originalillustrations (before reduction) must be largeenough so that the smallest letters are atleast 1.5 mm (1/16 inch) high when theillustrations are reduced to one of the abovewidths. If possible, letters on all originalillustrations should be the same size.Units and SymbolsMetric units according to the System ofInternational Units (SI) should be used.For more details, see G. F. Montgomery,“Metric Review,” JAES, Vol. 32, No. 11,pp. 890–893 (1984 Nov.) and J. G.McKnight, “Quantities, Units, LetterSymbols, and Abbreviations,” JAES, Vol.24, No. 1, pp. 40, 42, 44 (1976 Jan./Feb.).Following are some frequently used SIunits and their symbols, some non-SI unitsthat may be used with SI units (), andsome non-SI units that are deprecated ( ).

Unit Name Unit Symbolampere Abit or bits spell outbytes spell outdecibel dBdegree (plane angle) () °farad Fgauss ( ) Gsgram ghenry Hhertz Hzhour () hinch ( ) injoule Jkelvin Kkilohertz kHzkilohm kΩliter () l, Lmegahertz MHzmeter mmicrofarad µFmicrometer µmmicrosecond µsmilliampere mAmillihenry mHmillimeter mmmillivolt mVminute (time) () minminute (plane angle) () ’nanosecond nsoersted ( ) Oeohm Ωpascal Papicofarad pFsecond (time) ssecond (plane angle) () ”siemens Stesla Tvolt Vwatt Wweber Wb

INFORMATION FOR AUTHORS

Telephone: +81 3 297 73 8663Fax: +81 297 73 8670Email: [email protected]

Exhibit chair: Tadahiko NakaokiPioneer Business Systems DivisionTelephone: +81 3 3763 9445Fax : +81 3 3763 3138Email: [email protected]

Section contact: Vic GohEmail: [email protected]

Call for papers: Vol. 50, No. 12,pp. 1124 (2002 December)

Exhibit information:Thierry BergmansTelephone: +32 2 345 7971Fax: +32 2 345 3419Email: [email protected]

Call for papers: Vol. 51, No. 7/8,pp. 768 (2003 July/August)

Call for papers: Vol. 51, No. 9,pp. 871 (2003 September)

Exhibit information:Chris PlunkettTelephone: +1 212 661 8528Fax: +1 212 682 0477Email: [email protected]

Call for papers: Vol. 51, No. 1/2,pp. 112 (2003 January/February)

Convention preview: Vol. 51, No. 7/8,pp. 714–743 (2003 July/August)

sustainingmemberorganizations AESAES

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JOURNAL OF THE AUDIO ENGINEERING SOCIETYAUDIO / ACOUSTICS / APPLICATIONSVolume 51 Number 11 2003 November

In this issue…

Subjective Distortion Metrics

Audio Encoding with VideoConstraints

Vacuum-Tube Distortion Analysis

Acoustics of Historic ChineseTheaters

Features…

Binaural Audio

New AES OfficersAES Sections Directory

The Audio Engineering Society recognizes with gratitude the financialsupport given by its sustaining members, which enables the work ofthe Society to be extended. Addresses and brief descriptions of thebusiness activities of the sustaining members appear in the Octoberissue of the Journal.

The Society invites applications for sustaining membership. Informa-tion may be obtained from the Chair, Sustaining Memberships Committee, Audio Engineering Society, 60 East 42nd St., Room2520, New York, New York 10165-2520, USA, tel: 212-661-8528.Fax: 212-682-0477.

ACO Pacific, Inc.Acustica Beyma SAAir Studios Ltd.AKG Acoustics GmbHAKM Semiconductor, Inc.Amber Technology LimitedAMS Neve plcATC Loudspeaker Technology Ltd.Audio LimitedAudiomatica S.r.l.Audio Media/IMAS Publishing Ltd.Audio Precision, Inc.AudioScience, Inc.Audio-Technica U.S., Inc.AudioTrack CorporationAutograph Sound Recording Ltd.B & W Loudspeakers LimitedBMP RecordingBritish Broadcasting CorporationBSS Audio Cadac Electronics PLCCalrec AudioCanford Audio plcCEDAR Audio Ltd.Celestion International LimitedCentre for Signal ProcessingCerwin-Vega, IncorporatedClearOne Communications Corp.Community Professional Loudspeakers, Inc.Crystal Audio Products/Cirrus Logic Inc.D.A.S. Audio, S.A.D.A.T. Ltd.dCS Ltd.Deltron Emcon LimitedDigidesignDigigramDigital Audio Disc CorporationDolby Laboratories, Inc.DRA LaboratoriesDTS, Inc.DYNACORD, EVI Audio GmbHEastern Acoustic Works, Inc.Eminence Speaker LLC

Event Electronics, LLCFerrotec (USA) CorporationFocusrite Audio Engineering Ltd.Fostex America, a division of Foster Electric

U.S.A., Inc.Fraunhofer IIS-AFreeSystems Private LimitedFTG Sandar TeleCast ASHarman BeckerHHB Communications Ltd.Innova SONInnovative Electronic Designs (IED), Inc.International Federation of the Phonographic

IndustryJBL ProfessionalJensen Transformers Inc.Kawamura Electrical LaboratoryKEF Audio (UK) LimitedKenwood U.S.A. CorporationKlark Teknik Group (UK) PlcKlipsch L.L.C.L-Acoustics USLeitch Technology CorporationLindos ElectronicsMagnetic Reference Laboratory (MRL) Inc.Martin Audio Ltd.Meridian Audio LimitedMetropolis GroupMiddle Atlantic Products Inc.Mosses & MitchellM2 Gauss Corp.Georg Neumann GmbH Neutrik AGNVisionNXT (New Transducers Ltd.)1 LimitedOntario Institute of Audio Recording

TechnologyOutline sncPacific Audio-VisualPRIMEDIA Business Magazines & Media Inc.Prism SoundPro-Bel LimitedPro-Sound News

Psychotechnology, Inc.Radio Free AsiaRane CorporationRecording ConnectionRocket NetworkRoyal National Institute for the BlindRTI Tech Pte. Ltd.Rycote Microphone Windshields Ltd.SADiESanctuary Studios Ltd.Sekaku Electron Ind. Co., Ltd.Sennheiser Electronic CorporationShure Inc.Snell & Wilcox Ltd.Solid State Logic, Ltd.Sony Broadcast & Professional EuropeSound Devices LLCSound On Sound Ltd.Soundcraft Electronics Ltd.Sowter Audio TransformersSRS Labs, Inc.Stage AccompanySterling Sound, Inc.Studer North America Inc.Studer Professional Audio AGTannoy LimitedTASCAMTHAT CorporationTOA Electronics, Inc.TommexTouchtunes Music Corp.TurbosoundUnited Entertainment Media, Inc.Uniton AGUniversity of DerbyUniversity of SalfordUniversity of Surrey, Dept. of Sound

RecordingVCS AktiengesellschaftVidiPaxWenger CorporationJ. M. Woodgate and AssociatesYamaha Research and Development

Documents

Journal AES 2003 Nov Vol 51 Num 11