Tuning Curves and Pitch Matches in a Listener with a Unilateral, Low-Frequency Hearing Loss

Tuning curves and pitch matches in a listener with a unilateral, low-frequency hearing loss

Citation for published version (APA): Florentine, M., & Houtsma, A. J. M. (1983). Tuning curves and pitch matches in a listener with a unilateral, low- frequency hearing loss. Journal of the Acoustical Society of America, 73(3), 961-965. https://doi.org/10.1121/1.389021

DOI: 10.1121/1.389021

Document status and date: Published: 01/01/1983

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Download date: 02. Oct. 2021 Tuning curves and pitch matches in a listener with a unilateral, low-frequency hearing loss Mary Florentine CommunicationsResearch Laboratory (133FR), NortheasternUniversity, Boston, Massachusetts 02115 and ResearchLaboratory of Electronics(36- 761),Massachusetts Institute of Technology,Cambridge, Massachusetts 0213 9

Adrianus J. M. Houtsma •) ResearchLaboratory of Electronics(36- 755), Massachusetts Institute of Technology,Cambridge, Massachusetts 0213 9

{Received9 July 1982;accepted for publication6 December1982} Psychoacousticaltuning curvesand interaural pitch matcheswere measuredin a listenerwith a unilateral,moderately severe hearing loss of primarily cochlearorigin below 2 kHz. The psychoacousticaltuning curves, measured in a simultaneous-maskingparadigm, were obtained at 1 kHz for probelevels of 4.5-, 7-, and 13-dBSL in the impairedear, and 7-dB SL in the normal ear. Resultsshow that asthe levelof the probeincreased from 4.5- to 13-dBSL in the impairedear, {1 } the frequencylocation of the tip of the tuning curvedecreased from approximately2.85 to 2.20 kHz and {2}the lowest level of the maskerrequired to just maskthe probeincreased from 49- to 83- dB $PL. The tuningcurve in the normal ear wascomparable to data from other normal listeners. The interauralpitch matcheswere measured from 0.5 to 6 kHz at 10-dBSL in the impairedear and approximately15- to 20-dB SL in the normal ear. Resultsshow reasonable identity matches {e.g.,a 500-Hz tone in the impairedear wasmatched close to a 500-Hz tone in the normal ear}, althoughvariability was significantlygreater for pitch matchesbelow 2 kHz. The resultsare discussedin termsof their implicationsfor modelsof pitch perception. PACS numbers:43.66.Sr, 43.66.Ba, 43.66.Hg [JH]

INTRODUCTION hand,if the perceptionof pitch is basedon the temporal Thornton and Abbas(1980) found that the tips of psy- pattern of neural firingsin eachactive unit, then eachunit choacousticaltuning curveswere displacedto higher fre- respondingto a 1-kHz toneis expectedto be phaselocked to quenciesin three of four listenerswith moderate,low-fre- that tonein both the normaland impairedears. Therefore, quency,sensori-neural hearing losses. They interpreted their pitchmatches between the earsshould yield results closer to resultsas evidence that low-frequencysignals near threshold identity matches. werebeing detected by high-frequencyfibers in their listen- The purposeof the presentexperiment was twofold: {1 ) ers with displacedtuning-curve tips. This interpretationis to investigatepsychoacoustical tuning curvesfor various consistent with the animal data of Schuknecht and Neff' levelsof a low-frequencyprobe tone in a moderatelysevere {1952) and Sutton and Schuknecht {1954). The histologieson low-frequencysensori-neural hearing loss and {2)to investi- their animalswith maximum low-frequencyhearing losses gatepitch matchingin the samelistener. of 50 dB revealeda completeloss of apical hair cells and nerve fibers. In the presenceof a completeloss of sensoryunits at the I. METHOD apical end of the cochlea, the spread of the excitation A. Subject towardsthe oval windowcould be responsiblefor low-frequency signalsnear thresholdbeing detectedby the first The subjectwas a 31-year-old male with a moderately higher frequencyfibers available. Intact or partially da- severelow-frequency sensori-neural hearing loss in his fight maged low-frequencyhigh-threshold fibers, on the other ear. The subjecthad previouslyserved in psychoacousticex- hand, could providea secondarydetection system at high periments.Before the onset of data collection, the subject signalintensities and complicatethe generalshape of psy- was givena 20-min practicesession on eachtask. choacousticaltuning curves. His hearingloss was first noticedin early childhood. A particularlyinteresting question to ask of listeners The results of an audiometric test battery were consistent with low-frequency,sensori-neural hearing loss is how they with a lesionof primarily cochlearorigin in his fight ear and perceivepitch. If pitchperception is basedon the excitation normal hearing in his left ear. Pure-tonethresholds in dB pattern,we might expect that a pitchwill beperceived which SPL for his left and fight ears are shown in Fig. 1 by the correspondsto the frequencyof thetip of the psychoacousti- crosses.Thresholds in his fight ear were measuredin the cal tuning curve, at least at low intensities.On the other presenceof a contralateralmasker to eliminateauditory cues in the nontestear. The decreasein thresholdwith increasing Presentaddress: Institute for Perception Research (IPO), Den Dolech 2, frequencyin his fight ear is very steepfor a low-frequency Eindhoven, The Netherlands. hearing loss, averaging between 30 and 32 dB/oct. His

961 J. Acoust.Soc. Am. 73 (3), March 1983 0001-4966/83/030961-05500.80 ¸ 1983 AcousticalSociety of America 961

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FIG. 1. Psychoacousticaltuning curvesfor the normal ear (left) and the impairedear (right).The > 80- crosses represent absolute threshold for 250-ms tones. The filled symbolsrepresent the lev- D 60- els of the probe(4.5-, 7-, and 13- dB SL) and the corresponding untilled symbols representthe a. 40- levelof a pure-tonemasker need- Z ed to just mask the probe. The o 20- up-arrow indicatesthat the level of the masker needed to mask the probe exceeded100-dB SPL. 0-/; • i J I I I II I I I M • I • I • Ill I I I I o.• i • • o.• i 2 4 FREQUENCY (kHz) speechdiscrimination in his impairedear yieldeda PB-max reasons:(1)the simultaneous-masking paradigm iseasier to score of 76% at a test level of 90-dB HL. executeand (2) Turner (personalcommunication) found no In an attempt to further characterizethe nature of the significantdifference in the simultaneous-maskingversus heating loss,threshold was measuredat 1 kHz in the pres- forward-maskingparadigms in listenerswith low-frequency enceof a high-frequencymasking noise at severallevels. The hearinglosses. We measuredtuning curves in the following high-frequencymasker was a bandpassnoise with cutofffre- manner:First, the thresholdfor the 250-msprobe tone was quenciesof 2 and 4 kHz and skirtsof 48 dB?oct.The pres- determined in the absenceof the masker. Next, the test tone ence of the masker at 50 dB overall SPL increased threshold was set to a fixed level and the level of a variable-level masker at 1 kHz by approximately11 dB. The 60-dB-SPL masker toneneeded to just maskthe testtone was determined using a increasedthe thresholdby approximately13 dB. The 70-dB- Bekesytracking procedure. On eachstimulus presentation SPL maskerincreased threshold by approximately15 dB. the level of the masker was either increasedor decreasedby This shift in thresholdwith increasingmasker levels in low- 0.25 dB. Each data point wasthe averagepresentation level frequencyheating lossis consistentwith that observedby of the last 15 of a total of 20 reversals.The procedurewas Thornton and Abbas (1980). The resultsfrom our subject repeatedfor a numberof differentmasker frequencies cho- indicatethat for low levelsat 1-kHz detectionappears to be sento encompassthe entirerange of the tuningcurve. attributed to the higher frequencyfibers, but for levelsex- During measurementsof tuning curvesin the impaired ceeding15-dB SL the 1-kHztone may excite high-threshold ear, a contralateralmasker was presentedto eliminate the fiberswith a characteristicfrequency below the 2-kHz cutoff possibilityof cuesin the nontestear due to crossover.The of our masker.Alternatively, the limited increasein thresh- contralateralmasker was a widebandnoise encompassing old causedby our maskerscould be attributedto an excessive frequenciesbetween 0.2 and 20 kHz. The levelof the masker upward spreadof excitationfor test-tonelevels above 10-dB wasadjusted to effectivelymask, but not over-maskthe con- SL. tralateral cue. In addition to the contralateral masker, a maskerwas presentedin the test ear in two controlexperi- II. EXPERIMENT I: PSYCHOACOUSTICAL TUNING ments to eliminate the possibleinfluence of combination CURVES AS A FUNCTION OF LEVEL tones.This maskerwas a low-passnoise with a 800-Hz cutoff frequencyand its spectrumlevel was set 25 dB below the A. Procedure level of the probe. Psychoacousticaltuning curveswere measuredmon- aurally with a simultaneoustone-on-tone masking paradigm. Approximately300 msafter the onsetof the masker,a B. Results 250-ms probe tone was presented.After the offsetof the The psychoacousticaltuning curves are shownfor the probe, the maskerstayed on for another 300 ms for a total left andright earsin Fig. 1.The resultsfrom hisleft ear show maskerduration of 850 ms. Both the maskerand the probe a normaltuning curve when compared to datafrom listeners tone had rise and fall times of 25 ms. After the offset of the with normalhearing using a similarparadigm (i.e., Zwicker masker,there was a 500-mspause before the onset of the next and Schorn,1978; Florentine et al., 1980).The resultsfrom stimulussequence. Stimuli were presented through TDH-39 his fight ear show tuning curvesclearly displacedto the earphoneswith Zwislockicircumaural ear cushions.Tuning higherfrequencies. As the levelof the probewas increased curveswere measuredat 1 kHz for probelevels of 4.5-, 7-, from4.5- to 13-dBSL, thetips of thetuning curves decreased and 13-dBSL in his impairedear and for a problelevel of 7- from approximately2.85 to approximately2.20 kHz. Fur- dB SL in his normal ear. thermore, for only an 8.5-dB increasein the level of the A simultaneous-as opposedto a forward-masking probe,the tips of the tuning curvesincrease in level from paradigmwas used to measurethe tuning curvesfor two approximately49- to 83-dB SPL.

962 J. Acoust. Soc. Am., Vol. 73, No. 3, March 1983 M. Florentineand A. J. M. Houtsma:Low-frequency hearing loss 962

Downloaded 07 Aug 2012 to 131.155.151.138. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp The magnitudeof the shiftin the tip of the tuningcurve I I I I I I I I I I I I I 1 I appearedso striking that additional measurementswere I I made at probe levelsof 4-, 7-, 10-, and 13-dB SL using a continuous,sweep-frequency masker. Except for the continuous,sweep-frequency masker, the procedurewas the same asreported earlier. Results indicate only a slightdecrease in the frequencylocation of the tuning-curvetip for probelev- elsbetween 4- and 10-dBSL. (The tip of the tuning curveat 10-dB SL was at approximately2.65 kHz.) More precise 0.7 measurementswould be neededto establishthe significance of the differencein tuning-curvetip locationbetween 4- and I I I I I I I I I I I I I I I 10-dB SL. Nonetheless,our resultsshow a clearly shifted .5 I 2! 4 tuning-curvetip for the 13-dB-SLprobe. As the level of the TEST FREQUENCY (kHz) probewas increased from 4- to 13-dBSL the tip of the tuning curve increased from 58-dB SPL at 2.85 kHz to 83-dB SPL FIG. 2. The ratioFN/Fz of the frequenciesin the normaland the impaired at approximately2.20 kHz. earsfor equalpitch plotted as a functionof the testfrequency. Each point The resultsof the controlexperiments, which employed representsthe geometricaverage of measuresobtained with the standard the low-passnoise to maskpossible combination tones, were frequencyin rightand left ears.The verticalbars show plus and minus one standard deviation. similar to thosereported above, indicating no significantin- fluence of combination tones.

III. EXPERIMENT I1: PITCH MATCHES The pitchmatches at 7-dB SL (notshown here} revealed no pitchshift at 0.5 kHz but an averagepitch shift of approx- A. Procedure imately 30% at 1 kHz. Similar resultsare obtainedindepen- Interauralpitch matches were made for ten frequencies dentof whetherthe variableis in the normalor the impaired rangingfrom 0.5 to 6 kHz. A 500-mstest tone with rise and ear. fall times of 25 ms in one ear alternated with a similar comparisontone in the other ear, with a 300-msinterstimulus IV. DISCUSSION interval. The subjectwas instructedto adjustthe frequency A. Psychoacoustical tuning curves of the comparisontone to match the pitch of the standard. Test frequencieswere presentedin random order with re- Tuning curvesfor the sameprobe-tone frequency are placement.An averageof 30 {range20 to 37} pitch matches significantlydifferent between the listener'stwo ears,even at were made for each frequencyat or below 2 kHz and an the highestSL. The resultsshow displaced tips of the tuning averageof 14 {range12 to 18}matches were made for each curvestoward the higher frequenciesin the impaired ear. frequencyabove 2 kHz. These tuning curves show the same general features ob- A contralateral,wideband masker, described in the pre- servedby Thornton and Abbas (1980} and Turner et al. vioussection, was presented only during the intervalthat the (1983). stimuluswas presented to the impairedear. The level of the The upwarddisplacement of the tuning-curvetip indi- tonewas 10-dBSL in the impairedear and 15-to 20-dBSL in catesthat detectionof the probetone does not take placein the normalear. In addition,pitch matches were made for 0.5 the unitstuned to the probe-tonefrequency, but ratherin the and 1 kHz at a levelof 7-dB SL in theimpaired ear and 10-dB units tuned to much higher frequencies.These units are ex- SL in the normal ear. citedby the spreadof the excitationtoward the oval window. The listenerwas instructedto usea bracketingproce- The resultsalso show a dramatic changein the tuning dure, i.e., to adjust the comparisonalternately higher and curvesas the level of the probeis increasedfrom 4.5- to 13- lower in pitch than the standard,reducing the difference dB SL. The tip and the entirehigh-frequency portion of the until he perceivedequal pitch. No time limit wasimposed on tuningcurve clearly shifts toward the lowerfrequencies with the listener.When he finisheda pitch match, he presseda increasingprobe-tone level. Moreover,the minimum mask- button which initiated the next trial after a brief pause. er levelof the tuningcurves, i.e., the levelof the tip, showsa stronglynonlinear increase as the probe-tonelevel increases. Two explanationsfor this effectcome to mind:the shiftmay B. Results be causedby fibersthat respondto high-levelstimulation The resultsof the pitch matchesobtained at 10-dBSL althoughthey are damagedor it may be causedby high- aresummarized in Fig. 2 whichshows the frequencysetting thresholdfibers that are still intact. In any case,it appears in the normalear dividedby the matchedfrequency in the that there are no intact low-threshold fibers with center fre- impairedear as a functionof the test frequency.The most quenciesin the probe-frequencyregion as indicatedby the impressivefeature of theseresults is thevery large variability general upward shift of a tuning curve measuredat low below2 kHz. Despitethe largevariability it is clearthat, on probelevels. On the otherhand, probe tones at higherlevels the average,the matchingfrequencies differ betweenthe may excitehigh-threshold fibers---either intact high thresh- ears:at 1 kHz the pitchis higherby approximately20% in old fibersor damagedfibers---causing the tuning curve to the impairedear than in the normal ear. shift toward whereit is normally found.The notion of high-

963 J. Acoust.Soc. Am., Vol. 73, No.3, March1983 M. Florentineand A. J. M. Houtsma:Low-frequency hearing loss 963

Downloaded 07 Aug 2012 to 131.155.151.138. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp thresholdfibers is consistentwith Liberman's(1978, 1980} tion patterns.The possibilityalso exists that our listeneruses descriptionof low-spontaneous-activity,high-threshold fi- a combinationof time and placecues. bersin the cat'sVIIIth nerve,and with elevatedtips of phy- Althoughthe learninghypothesis is tenable,our results siologicaltuning curvesmeasured in the auditorynerve of aremore readily explained by pure-tonepitch theories based hearing-impairedcats by Kiang et al. {1970},Evans and on time patternsof Vlllth nerveunit firings{Wever, 1949; Klinke {1974},and Kiang and Moxon {1974}. Siebert,1970; Goldstein and Srulovicz,1977}. Each unit respondingto a 1-kHz toneis expectedto be phase-lockedto that tone,both in the impairedas well asin the normal ear, so B. Pitch matches that pitch matchesshould yield resultscloser to identity The presentresults are in agreementwith the recent matches. However, one should be careful not to conclude data reportedby Turneret al. {1983}.They reportedpitch from our discussionthat pure-tonepitch must be encoded matchesfrom severallisteners with low-frequencysensori- temporally in the VIIIth nerve. Induced pure-tonepitch neuralhearing losses showing matches in theregion of iden- shift effects{see Houtsma, 1981 for a recentreview} can be tity matches.Our pitch-matchingresults at 1 kHz showan quite large in listenerswith normal hearingand are hard to averagepitch difference of about20% at 10-dBSL andabout explainin termsof a purelytime-based theory. It is possible 30% at 7-dB SL. Thesepitch shiftsare muchsmaller than that in a listenerwith normal hearing, place information thepitch shift of morethan an octave that might be expected providesthe primarycue for pure-tonepitch, but that in the on thebasis of thetuning-curve tips. The implicationsof this presentcase the hearing-impairedlistener falls back on a discrepancywill be discussedin the nextsection. secondarytime-based cue when he is forcedto make pitch The largevariability in the pitchmatches below 2 kHz comparisonsfor toneswithin the elevated-thresholdregion is probablydue to dit•icultyin matchingtwo very different of his impairedear. percepts.Our listenerreported hearing pure tones at 2 kHz and abovein his impairedear but complexsignals in the ACKNOWLEDGMENTS frequencyregion below 2 kHz. He consistentlydescribed the We are indebtedto our subjectEric Williams for his 1.5- and 1.0-kHz tonesas very softtones presented simulta- commitment to this research. We would like to thank Dr. neouslywith a narrow-bandmasker in the frequencyrange S•6renBuus and Dr. SteveColburn for helpful comments. around the tone. He described the 0.5-kHz tone as a "hollow This researchwas carried out at the ResearchLaboratory of soundlacking a tonalbody." One wouldexpect the match- Electronics,Massachusetts Institute of Technologyand was ing of suchdifferent percepts to be very variable.For loud- supportedby the National Instituteof Health, Grant No. nessmatching, it hasbeen shown that variabilityincreases NS 11680-04. with the dissimilarityof the stimuli to be matched{Floren- tine et al., 1978}. The large variabilityin the pitch matchescontrasts Bekesy,G. (1960).Experiments in Hearing (McGraw-Hill, New York). sharplywith his almost normal frequency DLs obtained ina Evans,E. F., andKlinke, R. (1974)."Reversible effects of cyanideand fruse- separateexperiment. Roving-level, two-tone comparisons mide on the tuningof singlecochlear fibers," J. Physiol.242, 129-131. Florentine,M., Buus,S., and Bonding,P. (1978). "Loudnessof complex led to DLs at 1 kHz that wereapproximately the samein the soundsas a functionof the standardstimulus and the numberof compon- normaland the impaired ears at similarSLs. The largevari- ents," J. Acoust. Soc. Am. 64, 1036-1040. abilityin the interauralpitch matches is apparentlynot due Florentine,M., Buus, S., Scharf, B., and Zwicker, E. (1980). "Frequency to lack of frequencyresolution. Apparently, DLs should selectivityin normal-hearingand hearing-impairedobservers," J. Speech Hear. Res. 23, 646-669. only be inferredfrom measurementsby the methodof ad- Goldstein,J. L., and Srulovicz,P. (1977)."Auditory-nerve spike intervals as justment,when a monaural-matchingparadigm is used. an adequatebasis for aural frequencymeasurement," in Psychophysics and Physiologyof Hearing,edited by E. F. Evansand J.P. Wilson (Aca- C. Theoretical Implications demic, London),pp. 337-347. Houtsma,A. J. M. (1981)."Noise-induced shifts in the pitch of pure and Modern place theoriesof pitch perception(Bekesy, complextones," J. A½oust.So½. Am. 70, 1661-1668. 1960;Siebert, 1968; Zwicker, 1967}imply that thepitch of a Kiang, N.Y. S., and Moxon, E. C. (1974)."Tails of tuningcurves of auditory fibers," J. Acoust. Soc. Am. 55, 620-630. toneshould correspond to the placeof maximalexcitation, Kiang, N.Y. S., Moxon, E. C., and Levine, R. A. (1970)."Auditory-nerve whichought to beat thefrequency location of thetip of the activity in cats with normal and abnormalcochleas," in Sensorineural tuningcurve. Therefore, on the basisof our tuning-curve Hearing Loss,edited by G. E. W. Wolstenholmeand J. Knight (Williams data,we mightexpect our listener to matcha frequencyof 1 and Wilkins, Baltimore),pp. 241-273. Liberman, M. C. (1978). "Auditory-nerveresponse from cats raisedin a kHz in his impairedear to about2 kHz in hisnormal ear. low-noise chamber," J. Acoust. Soc. Am. 63, 442-455. The pitchmatches, however, show much smaller average Liberman,M. C. (1980)."Morphological differences among radial afferent pitchshifts and are closeto identitymatches. The finding fibers in the cat cochlea:An electron-microscopicstudy of serial sec- that pitch doesnot correspondto 'the placeof maximum tions," Hear. Res. 3, 45-63. Schuknecht,H. F., and Neff, W. D. (1952). "Heating lossesafter apical excitationdoes not invalidatethe generalconcept of pitch lesionsin the cochlea,"Acta Oto-Laryngol.42, 263-274. beingbased on excitationpatterns. Pitch may be derived Siebert,W. M. (1968)."Stimulus transformations in theperipheral auditory from featuresof the excitationpatterns other than the maxi- system,"in RecognizingPatterns: Studies in Living and •4utomaticSys- tems,edited by P. A. Kolers and M. Eden (MIT, Cambridge,MA). mum placeof excitation.For example,it couldbe that our Siebert,W. M. (1970)."Frequency discrimination in the auditorysystem: listenerhas learned through environmental exposure to as- Placeor periodicitymechanism," Proc. IEEE 58, 723-730. sociateequal pitch at the two earswith verydifferent excita- Sutton,S., and Schuknecht,H. F. (1954). "Regionalheating losses from

964 J. Acoust.Soc. Am., Vol. 73, No. 3, March 1983 M. Florentineand A. J. M. Houtsma:Low-frequency hearing loss 964

Downloaded 07 Aug 2012 to 131.155.151.138. Redistribution subject to ASA license or copyright; see http://asadl.org/journals/doc/ASALIB-home/info/terms.jsp inducedcochlear injuries in experimentalanimals," Ann. Otol. Rhinol. perceptionand low-frequencyhearing loss," J. Acoust. Soc. Am. 73, Laryngol.63, 727-753. 966-975. Thornton,A. R., andAbbas, P. J. (1980)."Low-frequency hearing loss: Wever,E.G. 11949}.Theory of HearingIWiley, New York}. Perceptionoffiltered speech, psychophysical tuning curves, and mask- Zwicker, E., and Feldtkeller,R. {1967}."Das Ohr als Nachrichtenemp- ing,"J. Acoust.Soc. Am. 67, 638-643. fanger" IS. Hirzel Verlag, Stuttgart}. Turner,C. W. (1982).(Personal communication.) Zwicker,E., andSchorn, K. 11978}."Psychoacoustical tuning curves in au- Turner,C. W., Burns,E. M., •nd Nelson,D. A. (1983)."Pure tone pitch diology,"Audiology 17, 120-140.

965 J.Acoust. Sec. Am., Vol. 73, No. 3, March1983 M.Florentine and A. J. M.Houtsma: Low-frequency hearing loss 965

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