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268 47100 H A R V A R D U N I V E R S I T Y

PSYCHO-ACo US T IC LABORATORY

Memorial Hall Cambridge Massachusetts

PERIODIC STATUS REPORT XXXVIII

Period covered 16 May- 1 December 1961

)XEROX

Research supported by theOFFICE OF NAVAL RESEARCH, U.S. NAVY

Contract Nonr-1866(15)•'roject NR 142-ZO,

theNATIONAL SCIENCE FOUNDATION

Grant G-19796,and the

NATIONAL INSTITUTES OF HEALTHGrant IiZ97,

I December 1961 - PN-94

L3 lffB~i~aa 51

CONTENTS

STAFF ............................................................. l

•EZA C 0.0.TE o .0 .ooo ..o.ooooe @ .. oo.oooooo.oo oo o o o o o o oe 9

PNR-258 The gap between the hearing of external and internalsounds* G. v. B~ce~sy .... ......... ..... .... ..... 0..2

PNR-259 The quantification of tonal volume. He So Terraceand S. S. Stevens ...................................2

PNR-263 Cormments on the measurement of the relative sizeof d-u notntals 'and microphonics in the cochlea.G. v. B41cesy ........ 000.0......,.....,..-....--...oo3

PNR-265 Can we feel the nervous discharges of the endorgans during vibratory stimulation of the skin?G. v. B4kesy ...... ......... s ee...... ....... .03

PNR-266 The scaling of subjective roughness andsmoothness. S. S. Stevens and Judith Rich .......... 3

PNR-267 Concerning the pleasures of observing, andthe mechanics of the inner ear. G. v. B4kesy .. 0...04

SPECIAL ACTIVITIES ................................... . .... ........ 4

RESEARCH IN PROGRESS *..sooe sees soe... 5

1. Fractionation of brightness under conditions ofsimultaneous contrast. J. C. Stevens .................... 5

2. Apparatus for ths study of contrast. R. Gerbrands,J. C. Stevens, and S. S. Stevens ....................... o.6

3. Subjective brightness of visual stimuli of variousdurations and luminances. T. Aiba *......................8

4. Subjective brightness during dark adaptation.G. van den Brink ........ ooo...........................8

5o Studies of loudness, softness, distance, andreciprocality. M. Guirao .................. *.. ...... 9

6. The transition level: a discontinuity in theintensitive difference limen. L. McMahon .. o..o.....o....9

7. A test of binocular sumution. L. R. Hamer,J. D. Kieffer, and A. W. Slawson oo..o.......oo.oo..lO

8. Subjective saturation of a color. Do W. Panek *......,,of0

CHECK-LIST OF REPORTS ...... .......... *......................1

P&IODIC STATUS REPORT XXXVIII

PSYCHI-ACOUSTIC LABORATORY

16 May - 1 December 1961

During the past six months the following have been membersof the research staff of the Psycho-Acoustic Laboratory.

S. S. Stevens, Ph.D., DirectorE. B. Newiian, Ph.D., Associate DirectorG. v. B6k6sy, Ph.D., Senior Research Fellow in PsychophsicsJ. C. Stevens, Ph.D., Assistant Prcfessor of PsychologyH. Eisler, fil. lic., Research FellowT. S. Aiba, Ph.D., Research FellowG. van den Brink, Dr.Phil., Visiting Research FellowMiguelina Guirao, Ph.D., Visiting Research FellowLois Hammer, M.A., Graduate StudentJ. D. Kieffer, B.A., Graduate StudentL. E. Mc14ahon, M.A., Graduate StudentD. W. Panek, B.A., Graduate StudentA. W. Slawson, M.A., Graduate StudentR. Gerbrands, Instrument Maker

RESEARCH COMPLETED

Since the 16th of May 1961 research has been completed andreports prepared on the following subjects. Reprints of these re-ports should be available within the next few months. A list ofrecent reports, and their PNR numbers, is included at the end ofthis report.

PNR-258 The GaE between the Hearing f _xternal and litrna Sounds..v. Besy.

The signal-to-noise ratio of the ear poses many unsolved prob-lems because of the ear's high sensitivity for external sound. Thereseem to be three systems involved in transforming the large but force-less vibrations of air particles into the smaller vibrations of astiffer molecular layer: (1) a hydraulic transformer in the middleear, (2) a shearing force around the hair cells, and (3) a moleculartransformer that concentrates all the forces onto a small layer. Itis probable that the mechanical displacements are transformed intoelectrical potentials by a triggering mechanism.

Relevant to this issue are the hearing of one's own voice andthe noises in the body of nervous origin. It may be that some formof neural inhibition decreases the importance of these internal noisesrelative to the external stimulus.

This article will appear in a forthcoming issue of the Journalof Experimental Biology.

PHR-259 The Quantification of Tonal Volume. H. S. Terrace and S. S.Stevens.

Tonal volume is defined as the apparent size or space-fillingattribute of a sound. In six experiments groups of 10 subjectsestimated the magnitude of the apparent volume of tones selectedfrom the equal-volume contours previously determined by Thomas. Foreach experiment two cuts, widely spaced, were made across each offive contours. These cuts defined a set of ten tones, each of adifferent frequency and intensity. In order to check the reliabilityof the magnitude estimations of volume, the tones from each cut wereused in at least two experiments.

In each experiment, one of the two tones from the middle contourserved as a modulus (standard), whose value was called 10.

The data from all six experiments confirm the general shape ofThomas's equal-volume contours. Magnitude estimations of volume hadquite similar values for all tones taken from the same contour. Theaveraged values from the six experiments indicate that the subjectivemagnitude associated with each of Thomas's equal-volume contours isapproximately twice that of the next smaller contour. From these con-tour values it follows that volume grows as a power function of soundpressure, and that the exponent increases markedly with frequency.

RiBEA1 CH Ci 3

The power functions showing the growth of volume with sound pressureconverge toward a common value at a level of 140 db. Volume behavesas a prothetic continuum and is not a power function of frequency.

This article will appear in a forthcoming issue of the AmericanJournal of Psychology.

PNR-263 Comments on the Measurement of the Relative Size of d-cPotentials and Microphonics in the Cochlea. G. v. Bgk~sy.

This Letter to the Editor will appear in the Journal of theAcoustical Society of America in January 1962.

PNR-265 Can We Feel the Nervous Discharges of the End Organsduring Vibratory Stimulation of the Skin? G. v. Bbk~sy.

The vibratory pitch sensation is a complicated function ofboth the frequency and the amplitude of the vibrations, andfrequency discrimination on the skin is thus inaccurate withina range of one or two octaves. Rutherford's telephone theoryfor pitch discrimination does not describe the pitch of vibratorysensations.

PNR-266 The Scaling of Subjective Roughness and Smoothness.S. S. Stevens and Judith Rich.

Preliminary experiments showed that the apparent roughnessand smoothness of 12 samples of emery cloths could be scaled bymagnitude estimation. Two 7-point category scales producedresults typical of prothetic continua: the plot of the categorysrtlo vs. the ratio scale is concave downward, but the curvaturedepends upon the spacing of the stimuli.

Magnitude estimations of roughness and smoothness producedstraight lines when plotted (log-log) against grit number. Inorder to determine the exponents of these power functions moreprecisely, two additional experiments were run with magnitudeestimation and one with cross-modality matching against loud-ness. All three experiments gave results that were power functionsof grit number with exponents in the vicinity of -1.5 for rough-ness and +1.5 for smoothness. (Grit number is proportional tothe reciprocal of particle size.) In terms of the average di-ameter D of the abrasive particles, roughness R, in units of ruks(1 unit - roughness produced by grit 320), is given by

R - 106.5D1"5.

Although judgments of smoothness turned cut to be nearly pro-portional to the reciprocals of the judgments of roughness, thisreciprocality was most clearly evident when 10 Os adjusted theintensity of a noise to produce a loudness that matched the apparentsmoothness. The cross-odality matches also confirmed the ex-

ponents deterined by magnitude estimation.

RESEARCH WMP EE

PM-267 Concerning the Pleasures of Observing, and the Mechanicsof the Inner Ear. G. v. Bbk~sy.

This article will be published as a Nobel Lecture in LesPrix Nobel en 1961.

SPECIAL ACTIVITIES

Georg von Be'ksy was the recipient of the 1961 Nobel Prizein Medicine for "his discoveries concerning the physicalmechanisms of stimulation within the cochlea." This climaxesthe many honors Dr. B~kesy has received since he came to thePsycho-Acoustic Laboratory in 1947. Almost simultaneouslywith the announcement of the Nobel Priz% Dr. Be'k~sy was honoredby an award from the Deafness Research Foundation.

S. S. Stevens gave an invited address at the meetings ofthe American Psychological Association. The address, entitled"The Surprising Simplicity of Sensory Metrics," was made inresponse to his ha-ing received the Moi ttn-uished Scientific

.S ARCH IN PROGRESS

1. Fractionation of brightness under conditions of simultaneouscontrast. J. C. Stevens. One half of the apparatus described

under item 2 in this report was used to repeat and extend ourexoeriments on contrast. With the right eye the observer vieweda pair of concentric fields. His task was to adjust the luminanceof one of the fields so that its brightness appeared to be somefraction or multiple of the other field. A dozen observers partic-ipated in each of three experiments.

(1) In the first experiment the observer attempted to adjustthe inner field so that it appeared to be 1/2, 1/4, 1/10, and 1/20as bright as the surround. These judgments were performed at eachof seven levels of the surround between 40 and 100 db re 10-10lambert. To control the adaptation, the observer -as dark-adaptedbefore the experiment, and the fields were exposed for 1.5 secwith intervals of 8 sec between exposures. The results were gen-erally consistent with the earlier findings. With a bright surround,the brightness of a target grows as a power function of its lum-inance. The exponent is very much larger than that of the stan-dard bril function (determined without contrast), and the sizeof the exponent increases with increasing luminance of the sur-round, at least up to about 80 db. With very bri-ht surrounds,the functions z xpear so steep that they are difficult to determinewith precision, and the results were not sufficiently clearcut todecide whether the exponent continues to increase beyond surroundlevels of about 80 db.

(2) In the second experiment the observer set the luminanceof the surround so that it looked twice or ten times as bright asthe inner disk. The results were quite consistent with those ofthe first experiment.

(3) The third experiment was like the second, except thatthe target and its surround were on continuously until the ob-server finished his adjustment. The purpose was to learnwhether the increased light adaptation would play a major rolein determining the slope of the brightness function under condi-tions of simultaneous contrast. Over the range explored (35 to95 db) there was a negligible effect produced by changing theconditions of adaptation from periodic to continuous exposure ofthe fields. The average settings in the two experiments werepractically the same.

RESEARCH IM PROGRES3

2. Aparatus for the Study of Contrast. R. Gerbrands, J. C.Stevens, and S. S. Stevens. An apparatus was constructed

for the study of simultaneous brightness contrast (see Fig. 1).This apparatus features a pair of large Lummer-Brodhun cubes,each of which serves to produce a pair of concentric fields (aninner disk and an outer surround, similar to the two fields seenin a Macbeth Illuminometer). With the left eye the observer seesthe inner and outer fields produced with one of the cubes, andwith the other eye he sees the two fields produced with theother cube. The figure shows only the half of the apparatusthat is used to stimulate the left eye; the other half is iden-tical, except that the parts are reversed, left for right.

The four fields are produced by four identical projectors.With 300-watt lamps in the projectors, the fields have a maximumluminance of about 110 db re 10-10 lambert. For most experiments,100-watt lamps are adequate. By means of mirrors and tubes, thebeams are directed to the appropriate part of the cube. The fluxfrom each projector can be independently controlled with neutraldensity filters and by an aperture of continuously variable size.Each aperture alone permits a continuous variation of more than40 db in the luminance of a field. Both the observer and theexperimenter can control each of the four apertures by means ofknobs. The luminances of the inner and outer fields can also beattenuated by the saine factor simultaneously by inserting aneutral density filter between the cube and the observer. Groundglass diffusion screens inserted between the cube and the lightsource insure uniformity of luminance over each field.

For convenient monitoring during an experiment, the photo-sensitive element of a W4elsh Densichron can be placed at a windowin any of the boxes containing the mirrors and filters. Since

readings taken at this point are proportional to the luminance ofthe fields seen by the observer, a change in the luminance of oneor more of the fields can be registered directly, in decibels, onthe logarithmic scale of the Derichron.

The apparatus is convenient for interocular matching in studiesrelated to brightness contrast. The observer's task may be tomatch the apparent brightness of the two inner fields when theouter fields have different luminance levels. By this procedureone can determine the combinations of target and surround lumi-ance that leave invariant the brightness of the inner disk. Studiesof this kind will be made in order to test an equation for simul-taneous contrast that was published earlier (J, opt. Soc. Amer.,1960, 50, p. 1139).

With the neutral filters replaced by various selective filters,the apparatus may also be used to study color induction.

Details regarding the construction of the Wier-Brodhun cubes:

each cube is made from two right angle prisms. These prisms are of

optical glass and have polished surfaces. The right angle faces are

EXPERIMENTER'S

APERTURE CONTROLS,

SURROUND SOURCE TARGET SOURCE

- APERTURES

SDIFFUSERS INTEROCULAR PARTITIONFILTERSMIRRORS OBSERVER

APPARATUS FOR THE STUDY OF CONTRAST

R3SEACH IN PROGRESS 8

47 x 47 rm. The long face of one of the prisms is treated withhydrofluoric acid so that all but a carefully masked centralportion of the surface is etched away. This masked portion isan ellipse 22 x 15.5 mm. The etching, in effect, raises the

ellipse above the rest of the surface.

The two prisms are then cemented together, long face to longface, in such a way that only the elliptical surface of theetched prism makes optical contact with the surface of the otherprism. The quantity of cement used must be just enough tospread evenly over the elliptical surface. An excess of cementwill spill over the area and will result in a non-circular fieldwhen the ellipse is viewed at 450 . The cement used is CanadaBalsam, treated in an oven at high temperature, so that it willsolidify at room temperature. in the cementing process both thecement and the prisms are heated to a temperature of 1500 C. Thehot cement is then applied to the hot prisms, one prism is placedon top of the other, and both allowed to cool slowly to roomtemperature. After cooling, the joint formed by the surfaces ofthe prisms is sealed with a strip of tape. The cube formed bythe cemented prisms is then ready for use in the apparatusdescribed above.

3. Subjective Brightness of Visual Stimuli of Various Durationsand Luminances. T. Aiba. The relation between duration and

apparent brightness of flashes produced by a glow-modulator tubewill be determined by the methods of matching and magnitudeestimation. The objects of this investigation are threefold.

First, the validity of Bloch's law will be examined at severalenergy levels. Although Bloch's law has been found to hold truewhen various threshold measures were used, evidence for itsvalidity for flashes at .su-rzthreshold levels is scanty and, atbest, based on a. few selected energy levels. Second, the bright-ness function for flashes of varying duration ill be determined.If the flash duration and luminance are perfectly reciprocal(i.e. if Bloch's law holds), then the power function that has beenfound for flashes of a fixed duration will presumably also holdfor flashes of varying duration. But in the region where Bloch'slaw does not hold exctly, the exponent of the function isexpected to be different. Third, the ranges of luminance andduration that cause the so-called "Broca-Sulzer effect" will beexamined. Although this effect has been rather well established,there is some doubt whether it shows up at all intensities. Theoptimal durations for producing the effect at various intensitylevels also need to be more clearly determined.

4. Subjective Brightness during Dark Adaptatio, G. van denBrink. The purpose is to trace the time cou'se followed bythe brightness of suprathreshold stimuli duriiig dprk adaptation.After the right eye has been light adapted, the subjectiveb mrihtness of various luminances will be measur3d as a functionOf tho time in t.e ddrk by means of a brightness comparison withstimuli presented to the dark-adaptt left eye. uring theprocess of dark adaptation, the brightness of tiv tzrget 0bserved

.RESEARCH I14 PROGRESS 9

with the right eye increases. Periodically, stimuli that aresubjectively weaker than the comparison stimulus in the left eyewill be presented to the right eye. The times at which stimuliin the left and right eyebeacme equal in subjective brightnesswill be measured for different luminances of the right-eye stimulus.

5. Studies of Loudness. Softness, Distance, and Reciprocality.M. Guirao. This study concerns two problems: (1) whether the

instructions to judge "distance" produce different results frominstructions to judge loudness and softness; and (2) under whatconditions judgments of softness are the reciprocal of judgmentsof loudness.

Fourteen experiments were carried out. The experimentsinvolved judgments of loudness, softness, and "distance" of puretones and white noise. The methods used included magnitude,estimation, magnitude production, and category production. Inthe experiments involving judgments of "distance," the resultswere essentially identical to the results obtained with estimatesof softness: they were approximately the reciprocal of theestimates of loudness. Reciprocality between estimates ofloudness and softness was shown more precisely with the methodof magnitude production than with the method of magnitudeestimation.

6. The Transition Level: A Discontinuity in the IntensitiveDifference Limen. L. McMahon. Experiments by D. Greenwood

indicate that the masked threshold for a pure tone in thepresence of a narrow band of noise is proportional to the sen-sation level of the noise up to a certain level called thetransition level. At this point, the masked threshold dropsabout 3 db; above the transition level the masked threshold isagain proportional to the noise intensity. PrelLminary exper-iments by Greenwood showed that this discontinuity at a tran-sition level also occurred when the masking stimulus was a puretone of the same frequency as the masked tone; in this case theexperiment could be considered an investigation of the inten-sitive difference threshold (PMn-91, 5 May 1961, p. 8).

Preliminary results oy the present experimenter (with oneobserver) show that the discontinuity at the transition levelcan be demonstrated by two methods: (1) for a fixed level ofthe steady (masking) tone, the observer adjusts the size of theincrement until it is just audible; (2) for a fixed ratio of theincrement to the sound pressure of the steady tone, the observeradjusts the level until the increment is just audible. Resultsof the two methods agree in showing a transition level at whichthe ratio of increment to steady level drops 6 tA 8 db.

With more satisfactory apparatus, now being fred, theparameters affecting this discontinuity in the . d thres-hold will be investigated more fully.

RESEARCH IN PROGRESS. 10

7. A Test of Binocular Summation. L. R. Hammer, J. D. Kieffer,and A. W. Slawson. A preliminary experiment has suggested

that magnitude estimations of stimuli viewed binocularly do notdiffer significantly from the estimations of the same stimuliviewed with only one eye.

Subjects were dark-adapted and seated in a light-proof booth.They were asked to judge the brightness of a round 3-degree spotwhose lumirance was changed in irregular order within the rangeof approximately 53 to 103 db above 10-10 lamberts. An exper-imenter in the booth operated shutters that allowed vision withthe right eye only, the left eye only, or with both eyes. Eachstimulus lasted 1 sec. The observer was asked to assign numbersproportional to the apparent brightness, beginning with anynumber he felt to be appropriate. Regardless of -Aetherone or two eyes were employed, the magnitude estimates of bright-ness -rew as. a -ower- function of sttaulus luminance with anexponent of approximately .35, and the intercepts of the powerfunctions were not significantly different from one another.

8. Subjective Saturation of a Color. D. W. Panek. An attemptwill be made to determine the relation between subjective

estimates of degree of saturation and the actual proportion ofa hue added to a gray. To this end, a mixer has been constructedwhich, by mixing a colored and a gray paper, presents to thesubject a colored spot which is continuously variable insaturation.

CICK-LIST OF REPORTS

issued by the

PSYCIO-ACOUSTIC LABORATORY., HAR VARD UNIVERSITYunder contract with the

U. S. MAVY, OFFICE OF NAVAL RESEARCHcontract Nonr- 1866(15)

No. Title Published by Authors

PNR-151* Preparatory and air- Rev. sci. Instruments, G. v. N&psydrivea micro-manipu- 1956, 27, 690-692lators for electro-phy' 1ooy

PF-152 'h- rasking of speech J. acoust. Soc. Amer., I. Pollackby rcpeated bursts cf 1954, 26, 1053-55,noise

PNR-153 Auditory sensitization J. acoust. Soc. Amer., J. R. Hughes1954, 26, 1064-1070

PNR-154 Decibels of light Phsics Today 1955 S. S. Stevensand sound 8(10), 12-17

PNR-155 On the evevaging. f Science, 1955, 121, S. S. Stevensdata 113-116

PNR-156 Tonal monaural di- J. acoust. Soc. 6mer., W. D. Wardplaucusis 1955, 27, 365-372

PNR-157 Factors determining J. acoust. Soc. Amer., J. Zvtslockithe sound attenuation 1955, 27, 146-154produced by earphonesockets

rfa.-ts Paradoxical direccfon J. acoust. Soc. Am-r., G. v. Bdkgsyof wavt ciav.l alorg 1955, 27, 137-145the cochlear partition

PNR-159 On the halving and J. acoust. Soc. Amer., E. C. Poultondoubling of white 1955, 27, 329-331 S. S. Stevensnoise

?NR-160 Bibliography on Cambridge: Harvard S. S. StevensHearing University Press, J. C. G. Loring

1955 Dorothy Cohen

PUR-161 The development of a J. acoust. Soc. Amar., J. ZwLslockisemiplastic earphone 1955, 27, 155-15.1socket

PM1-162 El oido y la vista Buenos Aires, 1954, S. S. .Stevens[The ear and the eye]. pp.408-416In Act. Prim- Conar.Extraord. Soc. InternatoAudiol.

*The list containing PNR.1 to PNR--50 is available on rv,.|st.

No. Title Published by Authors

PNR-163 The estimation of loud- J. exp. Psychol., S. S. Stevensness by unpracticed ob- 1956, 51, 71-78 E. C. Poultonservers

PNR-164 The apparent reduction J. acoust. Soc. Amer., S. S. Stevensof loudness: a repeat 1955, 27, 326-328 M. S. Rogersexperiment R. Herrnstein

PNR-165 Semiplastic earplugs J. acoust. Soc. Amer., J. Zwislocki1955, 27, 460-465

PNR-166 A note on recent devel- Proc. Nat. Acad. Sci., E. G. Weveropments in auditory 1954, 40, 508-512 M. Lawrencetheory G. v. B~k~sy

PNR-167 The moments of sample Glencoe, Ill.: Free M. S. Rogersinformation when the Press, 1955, pp. 101- B. F. Greenalternatives are equal- 108ly likely. In Infor-mation Theory in Psy-chology: Problems andMethods

PNR-168 The measurement of J. acoust. Soc. Amer., S. S. Stevensloudness 1955, 27, 815-829

PNR-169 The direct estimation Amer. J. Psychol.,, S. S. Stevensof sensory magnitudes -- 1956, 69, 1-25loudness

PNR-170 Ear protectors. In New York: McGraw-Hill, J. ZwislockiHandbook of Noise 1957, 27 pp.Control

PNR-171 Beitrag zur Frage der Arch. Ohr-usw. G. v. Bdk~syFrequenzanalyse in der Heilk.,1955, 167,Schnecke [On the ques- 238-255tion of frequency analysisin the cochlea]

PNR -172 Discriminative skill J. exp.. Psychol., J. S. Brunerand discriminative match- 1955, 49, 187-192 G. A. Millering in perceptual recog- C. Zimmermannition

PNR-173 Hearing and speech. In New York: McGraw-Hill, K. B. NewmanAmerican Institute of 1957, pp. 123-133Physics Handbook

PNR-174 The magical number 7 + 2 Psychol. Rev., G. A. Miller1956, 63, 81-97

No. Title Published by Authors

PNR-175 Human skin perception J. acoust. Soc. Amer., G. v. B~k~syof traveling waves 1955, 27, 830-841similar to those onthe cochlea

PNR-176 Psychophysical Noise Control, E. B. Newmaneffects of noise 1955, 1(4), 16-21

PNR-177 The design and J. acoust. Soc. Amer., J. Zwislockitesting of earmuffs 1955, 27, 1154-1163

PNR-178 Pendulums, traveling 16-nmn color film G. v. Bdk~sywaves and the cochlea (55 minutes) avail- R. L. Grason

able on loan

PNR-179 Current statui of Science, 1956, G. v. B4k~sytheories of hearing 123, 779-783

PNR-180 The perception of The Hague: Mouton G. A. Millerspeech. In For Roman & Co., 1956,Jakobson pp. 353-360

PNR-181 The calculation of J. acoust. Soc. Amer., S. S. Stevensthe loudness of complex 1956, 28, 807-832noise

PNR-182 Just noticeable dif- J. acoust. Soc. Aner., J. Zwislockiferences in dichotic 1956, 28, 860-864 R. S. Feldmanphase

PNR-183 Response-sequences Amer. J. Psychol., U. Neisserand the hypothesis of 1957, 70, 512-527the neural quantum

PNR-184 Estimations of loud- Amer. J. Psychol., J. C. Stevensness by a group of un- 1957, 70, 600-605 E. Tulvingtrained observers

PNR-185 Human memory and the IRE Trans., Sept. G. A. Millerstorage of information. 1956, IT2(3), 129-In Information Theory 137

PNR-186 Ratio scales and cate- J. em. Psychol., S. S. Stevensgory scales for a dozen 1957, 54, 377-411 E. H. Galanterperceptual continua

PNR-187 Simplified model to Proc. Nat. Acad. Sci., G. v. BAk6sydemonstrate the energy 1956, 42, 930-944flow and formation oftraveling waves similarto those found in thecochlea

Noe Title Published by AuthorsPNR-188 On the psychophysical hole Rev. S.S. Stevens

law 1951, 64, 153-181

PNR-189 Adaptation level vs. Amer. J. Psychol., S.S. Stevensthe relativity of judg- 1958, 71, 633-646ment

PNR-190 Problems and methods Psychol. Bull., S. S. Stevensof psychophysics 1958, 54, 177-196

PNR-191 Some measurements of J. acoust. Soc. Amer., J. Zwislockithe impedance at the 1957, 29, 349-356eardrum

NRR-192 Critical bandwidth J. acoust. Soc. Amer., E. Zwickerin loudness summation 1957, 29, 548-557 G. Flottorp

S. S. StevensPNR-193 Sensations on the J. acoust. Soc. Amer., G. v. Bdkgsy

skin similar to direc- 1957, 29, 489-501tional hearing, beats,and harmonics of theear

PNR-194 Concerning the form J. acoust. Soc. Amer., S. S. Stevensof the loudness func- 1957, 29, 603-606tion

PNR-195 Calculating loudness Noise Control., 1957, S. S. Stevens3(5), 11-22

PNR-196 The ear Sci. American, 1957, G. v. Bgkksy197(2), 66-78

PNR-197 In search of the bone- J. acoust. Soc. Amer.,, J. Zwislockiconduction threshold in 1957, 29, 795-804a free sound field

PNR-198 Some similarities be- Laryngoscope, 1958,. S. S. Stevenstween hearing, and seeing 68(3), 508-527

PNR-199 The variability of J. gen. Psychol., Me Wertheimerauditory and visual 1955, 52, 111-147thresholds in time

PNR-200 Neural volleys and J, acoust. Soc. Amer., G. v.- B~kdsythe similarity between. 1957, 29, 1059-1069zSome sensations pro-duced by tones and skinvibrations

No. Title Published by Authors

PIR-201 Heasuement, psycho- New Yurk: Wiley, S. S. Steve"physics and utility. 1959, pp. 18-64In Measuremen':: Def-initions and Theories

PNR-202 Soma imnedanc mesas- J. acoust. Soc. Amer.,, J. Zwislockiure ,n.t_? on normal 1957,, 29, 1312-1317and pat'.ological ears

PNR-203 Ear procection: effec- Noise Control, 1958 J. Zwislockitivauie; versus comfort 4(6), 14-15

PHR-204 On the cffect of prac- J. acoust. Soc. Amer., J. Zwislockitice and motivation on 1958, 30, 254-262 F. Hairethe threshold of audi- A. S. Feldmanbility H. Rubin

PhR-205 Fenestration of the PAL, 15 Sept. 1957 G. Kelemenlabyrinth: A bibliog-raphy (revision of ?NP-143)

PM-206 Threshold changes at Acta oto-larw . R. Hincheliffe4 Kc/s produced by Stockh., 1957, 47,bands of noise 496-509

PNR-207 On the minimum audible J. acoust. Soc. Amer., A. W. Hillsangle 1958, 30, 237-246

PNR-208 Stimulus spacing and J. exp. Psychol., J. C. Stevensthe judgment of loud- 1958, 56, 246-250ness

MR-209 A scale of apparent J. exR, Psychol., S. S. Stevensintensity of electric 1958, 56, 328-335 A. S. Cartonshock G. H. Shickman

PNR-210 Measurement and man Science, 1958', S. S. Stevens,127, 383-389

PNR-211 Ear protection Laryr._Zoscope, 1958 J. Zwislocki68(3), 486-497

PNR-212 Introduction and script: PAL, 27 Dec. 1957; G. v. Bd"syPendulums, traveling Larynroscope, 1958,waves and the cochlea 68(3), 317-328

1PN-213 Funneling in the ner- J. acoust. Soc. Amer., G.v. Ukwsyvous system and its 1958,. 30, 399-412role in loudness andsensation intensityon the skin

No. Title Published by Authors

PIH-214 Finger span: Ratio J, exp. Psychol., S. S. Stevensscale, cate-ory 1959, 57, 91-95 Geraldine Stonescale and And scale

PNR-215 Tactile v-,bc-tion: J. i',p, Psychol., S. S. StevensDynami,' of :ensory 1959, 57, 210-218intens, ty

PNR-216 Cross-Mczaliry vali- J. e-. PsYchol., S'. S. Stevensdat'ca of su-iective 1959, 57, 201-209scl".t tor lrudnesi,vibreaion, and electricshocV

PNR-217 On tL problem of vali- PAL May 1958 S. S. Stevensdat. a method fo-- ISO/ T/43, WG-5calculating loudne3s

PNR-218 Similarities between Psychol. Rev., G. v. BAksyhearing and skin sen- 1959, 66, 1-22sations

PhR-219 Subjective intensity Amer. J. Psychol., T. S. Reeseof coffee odor 1960, 73, 424-428 S. S. Stevens

PNR-220: Critical bands and the J. acoust. Soc. Amer., B. Scharfloudness of complex 1959, 31, 365-370sounds near threshold

PHR-221 The growth of subjec- Pensacola, Fla., J. C. Stevenstive magnitude with March 1958, pp,. 41-49 S. S. Stivenastimulus intensity.In Second ONR Sympo-sium on PhysiologicalPsychology

PMR-222 The perception of J. eMp. Psychol., J. C. Stevenorepetition rate 1959, 58, 433-440 G. M. Shickman

PHR-223 The loudness of complex J. acoust. Soc. Amer., B. Scharfsounds as a function of 1959, 31, 783-786the nunber of components

1PU-224, Synchronism of neural J.ec. ust. Soc. Amer., G. v. BAkdsydischarges and their 1959, 31, 338-349'demultiplication inpitch perception on theskin and in hearing

PNR-225 Scales of apparent J. e-z, Psychol., J. C. Stevensforce 1959,,, ' 58,;.AO-413 J. D. Mack

No. Title Published by Authors

PNtR-226 Growth of scnsation on J. tr. Psychol., J. C. Stevens

seven contxi:rs as meas- 1960, b9, 60-67 J. D. Mackured by fcr;e of hand- S. S. Stevensgrip

PNR-227 On the U,0:-r of the J. Lc':OLst. Soc. Amer., S. S. Steven6loudnes. ocaie 1959, 31, 995-1004

PNR-228 Neur-:1 1 nix along J. &ar.cet. Soc. Amer., G. v. bksythe q, :- cnd b-.t'*ecn 195S, ,1, 1236-1250the i,.:;. . aniL outer haircells cl th. cochlifa

PNR-229 Experienta'. models of Sprirgiield, Ill.: G. v. BUk~sythe c.,chlea wizh and Thomaj, 1960,wittout aer-ye aupply. pp. .- 20In 1,va- Mechaniems ofthe A 'iT oz, and Vestib-ular Systems

PNR-230 The quantification of Daedalus, Fall 1959, S. S. Stevenssensation 88(4), 606-621

PNR-231. Auditory facilitation J. F.coust. Soc. Amer., H. Rubinfollowing stimulation 1960, 32, 670-681at low intensities

PR-232 The form of the loudness Amsterdam: Elsevier B. Scharffunction near hrechold. (in press) J. C. StevensIn Proc. 3rd Int. Conar.Acoustics.

PNR-233 Vber die Glcj.chart.Pkeit Amsterdam: Elsevier G. v. Bkfsyeiniger nervt~ser 2rozesse (in press)beim Hbren und Vibra-tionssinn. In Pro. 3rdInt. Contr. Acoustics

PNR-234 Warmth and cold: dynamics J. ePx. Pchol, J. C. Stevensof sensory intensity 1960, 60, 183-192 S. S. Stevens

PHR-235 Lateralization of high- J. acoust. Soc. Amer., A. W. Millsfrequency tones 1960, 31, 132-134

mNR-236 Psychophysics of sen- New York: Tech. Press S. S. Stevens

sory function., In and Wiley, 1961, pp.

Sensory Communication 1.33; Amer. Scientist,1960, 48, 226-253

PNR-237 The auditory input-out- Ams, rdam; Elsevier S. S. Stevensput function. In Proc. (in press)3rd rnt. Consr. Acoustics-

No. Title Published by Agthors

PR-238 Is there a quantal New York: Tech. Press S. S. Stevensthreshold? In Sensory and Wiley, 1961, *,.

Co munication 806-813

PNR-239 On the new psycho- Scand. J, Psychol., S. S. Stevensphysics 1960, 1, 27-35

PNR-240 Ratio scales, partition New York: Wiley, S. S. Stevensscales and confusion 1960, pp. 49-66scales. In PsychologicalScalirs: Theory andApplications

PINR-241 The influence of inhi- Fort Knox, Ky.: U.S. G. v. BUk~sybition on the sensation Army Med. Res. Lab.pattern of the skin Report No. 424, 1960,and the eye. In jg- pp. 50-62sium on Cutaneous Sen-sitivity

PM-242 Voice level: Autophonic J.acoust. Soc. Amer., H. L. Lanescale, perceived loud- 1961, 33, 160-167 A. C. Catanianess, and effects of S. S. Stevenssidetone

PNR-243 Neural inhibitory units J. opts Soc. Amer., G. v. BIk&syof the eye and skin. 1960, 50, 1060-Quantitative descrip- 1070tion of contrast pheno-mena

PR-244 The binaural sumation J. acoust. Soc, Amer., G. S. Reynoldsof loudness 1960, 32, 1337-1344 S. S. Stevens

flIR-245 Physiological zero and (in press) J. C. Stevensthe psychophysical law. S. S. StevensIn Proc. 16th Into Connr.Psycholozy

PmR-246 The dynamics of visual PAL, August, 1960 S. S. Stevensbrightness J. C. Stevens

Pm.-247 The pitch sensation and J. acoust. Soc. Amer., G. v. B&kdsyits relation to, the 1961, 33, 341-348periodicity of thestimulus

PNR-248 To honor Fechner and Science, 1961, 133, ,5. S. Stevensrepeal his law 80-86

IMR-249 Toward a resolution of Psychometrika, 1961, S. S. Stevensthe Fechner-Thurstone 26, 35-47legacy

No. Title Published by Authors

PNR-2S0 On the form of learn- J. exp. Anal. Behav., J. C. Stevensing curves H. B. Savin

PNR-25l Are surgical exper- Laryngoscope, 1961, G.v. Bdkdsyiments on human sub- 71, 367-376jects necessary?

PNR-252 Auditory masking and J. acoust. Soc. Amer., D. D. Greenwoodthe critical band 1961, 33, 484-502

PNR-253 Procedure for calcu- PAL, 1 March 1961 S. S. Stevenslating loudness, Mark VI ISO/TC/43 WG-5

PNR-254 Concerning the funda- J., acoust. Soc. Amer., G. v. Bdkdsymental component of 1961, 33,. 888-896periodic pulse patternsAnd modulated vibra-tions observed in thecochlear model withnerve supply

PNR-255 The dynamics of subjec- New York: Reinhold 3. C. Stevenstive warmth and cold. In (in press) S. S. Stevens.Fourth Symposium onTemperature

PNR-256 Surprising simplicity Amer. Psychologist, S. S. Stevensof sensory metrics

PNR-257 Abweichungen vom ohm'- Akust. Beih., G., v. Bdkiisy,schen Gesetz der Frequenz- Acusticaauflbsung beim Hb~ren

PNR-258 The gap between the J. exp. Biol., G. v. Bdkdsyhearing of external and:internal sounds

PNR-259 The quantification of Amer. J. Psychol. H. S. Terrace.,tonal volun S. S. Stevens.

PNR-60 Subjective scale of H.. Eislerforce for a largemuscle group

*PNR-261 On the problem of H. Eislercategory scales inpsychophysics

PNR-262 Empirical test of a H. Eislermodel relating magnitudeand category scale&

N~.Title Published byAuthors

PM-263 Camments on the measure- J., acoust., Soc. Amr., G.. ksment of the relativesize of d-c potentialsand microphonics in thecochlea

PNR-264 Quantifying the sensoryexperience S. S. Stevens

PNR-265 Can we feel the nervous J.,acoust. Soc. Amer., G. v. Bdkdsydischarges of the endorgans during vibratorystimuilation of the skin?

PHR-266 The scaling of subjective S. S. Stevensroughness and smoothness J. Rich

PN-267 Concerning the pleasures of. te. 3?iX Nobel, G. v. B3&4 syobserving, and the mechan-ics of the inner ear