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J. Audio Eng. Soc., Vol. 56, No. 3, 2008 March 217

next to computers. In such cases it can

be very hard to identify the ENF, as

shown in Fig. 9, where the top plot

shows the spectrum recorded from a

voice recorder placed next to a laptop

computer, which is predominantly

broadband noise. Mobile phones can

have a similarly disturbing effect. He

also shows evidence that even very lowbit-rate compression schemes such as

MP3 at 8 kbit/s manage to preserve the

basic ENF component information when

recording other audio information such

as the sound in a room.

One interesting application of ENF

analysis that is shown by Brixen is its

use in analyzing sections of a recording

that may have been mixed together with

another recording. An example is

shown in Fig. 10 where it is clearly visi-

ble that two ENF components are

present for a period of time, before

which only one component can be seen.

CONCLUSIONThere is clearly a wide range of differ-

ent ways in which the challenging prob-

lems of forensic audio analysis can be

tackled. Like fingerprints, the mains

power frequency can provide a unique

identifier for the time a recording was

made and whether more than one

recording is present. Edits may be spot-

ted and voice patterns matched using

sophisticated digital signal processing.

Although in practice these processes are

not usually as miraculous or conclusive

in bringing evil-doers to justice as

implied by television series such as CSI,

they can help to generate a wide range

of supportive evidence capable of deter-

mining the veracity of recordings.

Forensics Audio Analysis

Editors note:The papers reviewed in this

article, and all AES papers, can bepurchased online at and

. AES

members also have free access to a large

number of past technical review articles

such as this one and other tutorials from

AES conventions and conferences; go to

.

The upcoming AES 33rd International

Conference, June 57 in Denver, will be

devoted to the topic Audio Forensics

Theory and Practice. For more information

go to .

OF THE

SECTIONSWe appreciate the assistance of the

section secretaries in providing the

information for the following reports.

Statements reported here are the per-sonal opinions of the presenters, which

may not represent the opinions of the

AES or the audio industry at large.

NEWS

Clark discusses car audioin Motor CityThe Detroit Section held its February

7 meeting at Alpine Electronics. After

new officers were elected at a short

business meeting, David Clark gave a

presentation entitled Perceptual

Transfer Function (PTF) Measurement

System, a Progress Report. He began

with some history on automotive

audio, discussing the development of

the technology from 1930 Motorola

car radios to present day. The first

Bose system (in a 1983 Cadillac) was

discussed, and the more recent B&O

system for the Audi A8 was also pre-

sented. He gave an overview of his

Listening Technology subjective eval-

uation technique. This method is

widely used within the automotive

industry and has been the inspiration

for Clarks advancement with PTF.

The interest in automotive audio is

growing, and the needs for industrial

processes and procedures to ensure

consistent high-quality output are as

relevant as ever. It was this realizationthat inspired Clark to develop Listen-

ing Technology in the 1990s. By

agreeing on an ideal sound or goal

for a system, trained evaluators are

able to build conclusions about a sys-

tem from small comparison tasks. The

results are reliable, unbiased evalua-

tions as free from opinion and emotion

as possible.

The goal of PTF is to use objective

measures to simulate subjective or

perceptual responses to a sound sys-tem. Starting with frequency

responseor to use perceptual lan-

guage, tonal balancehigh-level

analysis of a spectrum allows

attributes to be extracted and given a

score by the computer. This has been

extended to loudness tests with a mul-

titone test measuring compression and

distortion simultaneously.

Clarks most advanced work with

PTF is location detection. Using an

advanced ear-brain model sound stage,

imaging and ambiance can be mea-

sured using interaural level differ-

ences, interaural time differences, and

interaural group delay; this was

demonstrated at the meeting. Atten-

dees could see how the different

image-detection methods work at dif-

fering frequency ranges and could see

the detection of left, right and phan-

tom images.

Alan Trevena

Ilmenau SectionreactivatedIn December, 80 interested students

met to reactivate the Ilmenau StudentSection and discuss the development

of student activities in the field of

audio engineering. The event took

place at the Fraunhofer Institute for

Digital Media Technology in Ilmenau,

on the initiative of Karlheinz Branden-

burg, AES governor. Brandenburg is

the director of this research institute

and well known for his important role

in the development of MP3.

With the support of the Fraunhofer

Institute as well as the establishmentof media technology courses at the

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of the audience on this topic led to a

lively discussion. The audience greatly

appreciated Beristains lecture. Every-

one extended thanks to him for an

excellent lecture that fortified the

efforts of the Mexico Section on edu-

cating and connecting professionals

through its activities.Following the lecture, more details

were presented on the 2008 AES

International Latin American Confer-

ence New Concepts in Audio, which

will be held April 2729 at the World

Trade Center in Mexico City.

On behalf of all the members of the

Mexico Section, we want to thank

everybody at the AES for their support

and for helping us in our efforts in

consolidating the section for the pro-

fessional industry in Mexico. Weinvite you all to the conference. Please

go to

for more information. See you in

Mexico!

Mintel Alonso

MTSU visits Harrison

On invitation from Harrison Con-

soles, maker of the digital consoles

used in premier film, postproduction,

and broadcast facilities throughoutthe world, the MTSU Student Sec-

tion attended an open house at the

companys Nashville headquarters

duces a homogeneous soundfield fill-

ing the entire room. And the group

heard about other developments

Fraunhofer IDMT is working on.

Beristain on control room

acousticsThe Mexico Section held its January

29 meeting at Estudio 19 Recording

Studios, Mexico City, with over 50

people attending. This first meeting in

2008 was a presentation on special

issues and considerations in proper

control room acoustic design and con-

struction by Sergio Beristain, who is

widely recognized for his outstanding

work in this area. He began by analyz-

ing the whole scope of variablesinvolved in an acoustic design. Next

he discussed materials and his favorite

building techniques. The keen interest

Technische Universitt, Ilmenau has

become a center of excellence in the

research field of audio technologies.

In order to develop and promote thestudent activities in this area, employ-

ees of Fraunhofer IDMT and the Insti-

tute and media technology students of

the Technische Universitt Ilmenau

organized this event for reactivating

the Ilmenau Student Section.

In the future, the Ilmenau Student

Section will bundle the various

research activities in the field of audio

engineering and report the latest

advances in technology and applica-

tions through a strong representationof student work at AES international

conferences. The strong scientific col-

laboration between the TU Ilmenau

students and engineers of Fraunhofer

IDMT will play an important role in

the success of the section.

The idea of reactivating the student

organization attracted a lot of interest

from all attendees. Brandenburg

pointed out that Only by cooperation

and communication with other stu-

dents and leading international scien-tists can research move forward. The

AES Student Section offers young sci-

entists and students international con-

nections and a platform to exchange

informationan important corner-

stone for scientific progress.

A demonstration of IOSONO, the

innovative wavefield synthesis sound

system of the Ilmenau Fraunhofer

Institute, gave the attendees a practical

insight in the research developed by

the institute. This is a main researchtopic at the Fraunhofer IDMT. It pro-

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218 J. Audio Eng. Soc., Vol. 56, No. 3, 2008 March

Karlheinz Brandenburg facilitated thereactivation of the Ilmenau StudentSection

Sergio Beristain, one of the mostrenowned acoustic specialists inLatin America

From left, Robert Luckey, Michael Zuehsow, Jordan Shirks, and Michael Gregoryduring MTSU tour of Harrison Consoles

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discussion of several excerpts from a

2002 concert shoot featuring music

from the Chieftains Down the Old

Plank Road: The Nashville Sessions

at the Ryman Auditorium done by

Gordon and Repp. The presentation

also included information about the

opportunities available to audio engi-

neers in the television industry. Gor-don also gave the members valuable

advice on succeeding at internships

and entry-level jobs. His advice was,

just show up, do what youre asked,

and be pleasant about it.

Robert Luckey

NY hears from archivingprosThe 92nd Street Y in New York City

has a substantial historical archive,much of it on magnetic tape. Today,

performances are recorded on Pro

Tools systems. As the New York Sec-

tion learned at its February 12 meeting

at NYUs Jazz Performance Space,

David Nolans job at the 92nd Street

Y encompasses both conversion of the

tape archive to digital format and

preservation of new recordings.

Original tapes were rarely labeled in

a standardized (or even adequate)

fashion. For example, an entire shelfof tapes where each box contains

mixing. Using tracks from one of his

many recent projects, MTSUs new

SSL Duality console, and a variety of

outboard gear, he then demonstrated

and explained several of his favorite

and most useful mixing techniques.

Finally, after a short break, Chuck

fielded several questions from the

members. This Q&A session led tomany interesting anecdotes and

insights on the mixing process, audio

technology, and the recording industry

in general.

Robert Luckey

Gordon and Repp discussChieftans projectIn an ongoing effort to bring in a

diverse field of guest speakers on top-

ics not usually covered in music

recording classes, the MTSU StudentSection hosted independent television

director Robert Gordon and mix engi-

neer Mark Repp of MTV Networks on

February 6. The two spoke at length

about the process and challenges of

recording and mixing live audio for

television, and later, editing and

postproduction. Every aspect of the

process from initial concept to final

mixing was covered, including inter-

esting and useful information on mik-

ing, signal flow, and communication.The focus of the event then turned to a

on January 29. The night began with

refreshments and an informal meet

and greet with Harrisons engineers

and several other members of the

Nashville audio community. Once

everyone had their fill, the attendees

received a presentation on Harrisonssystem architecture and the features

of the nights main attraction, a 30-

foot-long, 112-fader, 384-input

MPC-4D film console. The event

then moved to the assembly floor

where two newly assembled con-

soles, the MPC and a smaller Trion,

were on display. Everyone had the

opportunity to touch and explore

both consoles while talking to sev-

eral Harrison engineers. The open

house was a rare opportunity for thesection members to see such a large

and complex console, as such con-

soles are used only in the most exclu-

sive and restricted film mixing stages

in the world. Both of the consoles on

display were purchased by Mosfilm,

the largest film production studio in

Russia, and were scheduled to be

shipped shortly after the event.

Robert Luckey

Chuck Ainlay mixes at MTSUIn the latest installment of the MTSU

Student Sections long-running series

of mixing events with industry profes-

sionals, the chapter hosted acclaimed

engineer Chuck Ainlay on February 2.

Chuck began the seminar by introduc-

ing himself and giving a brief sum-

mary of his history in the Nashville

music industry. He then went on to

discuss the technology and gear he

uses on a daily basis, his reasons for

choosing them, and how he uses themto his advantage while tracking and

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J. Audio Eng. Soc., Vol. 56, No. 3, 2008 March 219

Chuck Ainley, center, with MTSU students

Robert Gordon, left,and Mark Repp

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such as a machine called IRENE that

can play a disc recording by analyz-

ing a high-resolution image of the

disc. McCoy reports that this is partic-

ularly valuable for playing broken

discs, which would be difficult or

impossible to play with a conven-

tional stylus.The NAVCC is grappling with the

problem of preserving born digital

material, which may arrive in many

different formats. They will always

seek to preserve a copy in the original

format, although access copies may be

created in other standardized formats.

They have a facility that captures

material from the Internet, which has

been dubbed the TIVO room. Much

more information on NAVCC facili-

ties can be found online at. The

presentations were followed by a

lively audience discussion.

Noah Simon

Schueller reviewsPhilippine music archiveDietrich Schueller, director, Phono-

grammarchiv, Austian Academy of

Science, spoke at the February 21

meeting of the Philippines Sectionabout his evaluation of the progress in

the preservation and digitalization of

the Jose Maceda Collection. The col-

lection was recently included in the

Memory of the World Register of the

United Nations Educational, Scien-

tific, and Cultural Organization

(UNESCO). This collection, known as

the Jose Maceda Philippine Music

an entire floor dedicated to audio. It

includes a media prep area where

discs and tapes can be properly

cleaned prior to playback, critical lis-

tening rooms, and transfer studios.Current practices, which are still

under development, call for transfer of

analog recordings to 96-k, 24-bit

broadcast WAV files. Digital restora-

tion work is never done during the

original transfer. Metadata is extracted

and entered into a database. The digi-

tal files are stored on a large local file

server, with tape backup. Copies are

also sent via fiber links to off-site

backup facilities. Files will be

migrated to more modern servers asneeded.

In addition to preserving original

media, NAVCC seeks to preserve

legacy equipment needed to play the

original media. They have an antique

format room, which among other

things includes a large collection of

wire recorders. They also have some

new methods of playing old media,

only the notation Poetry and a date

poses a real problem for the archivist,

who must then review the recording to

create metadata.

Recordings at the 92nd Street Y arenow archived as Pro Tools sessions.

Nolan stressed the importance of

establishing a style for track names

and layout and ensuring that all ses-

sions conform to that style before

committing them to the archive. He

refuses to call anything a backup if its

stored on site. Two copies sitting on

the same shelf? That's not a backup.

Brad McCoy, the meetings second

presenter, works at the National

Audio-Visual Conservation Center inCulpepper, Virginia, 60 miles south of

Washington. This new 415,000-

square-foot campus, which was

created in collaboration with the

Packard Humanities Institute, includes

underground storage space for the

Library of Congresss moving image

and sound recording collections and

modern, well-equipped workspace for

the archivists.

McCoy agreed with Nolan

on the importance of generat-ing adequate metadata, con-

verting it to a standardized

format, and storing it in a

database.

He told the group that the

AES Library, an extensive

collection of audio-related

publications donated by AES

to the Library of Congress, is

now on display at NAVCC. It

can be visited by appointment.

The Conservation Building, atthe center of the campus, has

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220 J. Audio Eng. Soc., Vol. 56, No. 3, 2008 March

NY Section meeting:from left, JohnChester, AESpresident-elect JimAnderson, meetingmoderator RobertAuld, andpresenters Brad

McCoy and DavidNolan

Philippines Section meeting: from left, Dayang Yraola, Mark Laccay, Martin Galan, DietrichSchueller, Ramon Santos, Dodie Lucas, and Jiggs Hermano

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recording facilityin their shipping

room. He also designed their disc-cut-

ting facility. Contemporary did have

some state-of-the-art equipment for

the time, with Ampex tape recorders, a

stereo Westrex lathe, and AKG and

Neumann mikes.

Bill Smith, now a retired University

of Washington Emeritus Professor of

Music, gave some of his recollectionsof those days and got reacquainted

with Roy for the first time in decades.

Bill went on to do five albums at Con-

temporary with Roy engineering. He

recalled the warehouse-cum-studio

being spartan, but with Roy still able

to get a marvelous sound. Close mik-

ing and some baffles were used, and

the ladies room got pressed into ser-

vice as an echo chamber.

Tom quoted some of the accolades

others said about Roys recordingfrom his Stereophile article, including

this from recording and mastering

engineer Bernie Grundman: Roy did

a lot for this industry. He showed us

all how good it could be. His best

recordings are not just good for their

era. They are some of the best-sound-

ing recordings of all time.

The evening finished with a Q&A

session, and by playing Sonny Rollins

from his Airegin album (Nigeria

spelled backwards). Gary Louie

how to improve the AES. Then Tom

Conrad sat down with Roy, assisted

by the occasional playing of musical

excerpts, and discussed the studios,

artists, equipment, and techniques of

the early analog tape days.

While other engineers may have

received more publicity, Roys work

stands up to anyones. Capitol

Records first engineer, he recorded,among others, Nat King Cole, Frank

Sinatra, Dean Martin (including

Thats Amore), Peggy Lee, Kay

Starr, Jo Stafford, Stan Freberg, and

the Stan Kenton Band (a louder band

than Navy planes, he says).

Later, lured to Contemporary

Records, he worked on many jazz

classics featuring the likes of Barney

Kessel, Ray Brown, Shelly Manne,

Art Pepper, Andr Previn, Leroy Vin-

negar, Sonny Rollins, Ornette Cole-man, Bob Cooper, Curtis Counce,

Teddy Edwards, Victor Feldman, and

Hampton Hawes.

Roy told of his early years and how

he got a job at Capitol Records in the

Quality Control Department, testing

record players that Capitol made and

sold. Ultimately, he advanced to the

recording studio as an engineer, later

going to work for Lester Koenig and

Contemporary Records.

By 1956, Roy was charged withbuilding the Contemporary Records

Tape Collection, records the tradi-

tional music of 68 ethnolinguistic

groups before these styles vanish or

substantially change as a result of

social change and cultural globaliza-

tion. Launched in 1992, the collection

consists of more than 2000 hours of

tape recordings. It includes cassettetapes, field notes, photographs of dif-

ferent musicians and instruments, and

some films. It has been preserved and

used by academic scholars in the con-

tinuing study of Philippine traditional

music. For more information on the

collection go to .

The University of the Philippines

Center for Ethnomusicology throughits executive director Ramon Santos

and technical assistant Dayang Yraola

are spearheading work on the Jose

Maceda Collection with the technical

assistance of Dodie Lucas and Martin

Galan, members of the AES Philip-

pine Section. Digitalization work will

be done by Mark Laccay, an officer of

the Institute of Audio and Acoustics,

the educational arm of the AES Philip-

pine Section.

Martin Galan

An evening withRoy DuNannThe Pacific Northwest Sections

November meeting was a very special

evening with an unrecognized giant of

the recording engineering business,

Roy DuNann, long retired and living

near Seattle. Chance circumstances

and the discovery of an April 2002

Stereophile magazine article on himby jazz writer Thomas Conrad led to

this meeting. Conrad was enlisted to

be the meeting host/interviewer, and

an RSVP capacity audience of 50 (23

being AES members) gathered at

Opus 4 Studios in Bothell, Washing-

ton. Also on hand was clarinetist Bill

Smith, who recorded five albums with

Roy in the 1950s and 1960s at Con-

temporary.

PNW Chair Rick Chinn opened the

meeting, with AES president BobMoses on hand to ask the audience

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J. Audio Eng. Soc., Vol. 56, No. 3, 2008 March 221

PNW tribute to Roy DuNann: from left, Bill Smith, Roy DuNann, and Tom Conrad

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