• Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Journal of the Acoustical Society of America

SECTION LISTING

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

May 1983

Volume 73, Issue S1, pp. S1-S106

Return to All Sections
back to top
RSS Feeds
back to top Session U. Psychological Acoustics IV: All Things Considered (Poster Session)
Contributed Papers
FREE

Sound localization acuity in mammals and its relation to visual fields (A)

Rickye S. Heffner and Henry E. Heffner

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S42-S42 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
It has often been suggested that the ability of mammals to localize sound is closely tied to visually locating the sound's source. If this is so, then there might exist some parameter of vision which is closely correlated with sound‐localization ability. To determine whether some aspect of the visual fields might be linked with sound localization, the extent of the binocular and panoramic fields was measured in fourteen species of mammals whose sound localization acuity is known. It was found that the degree of binocular overlap in mammals is positively correlated with sound‐localization acuity for frontally placed sound sources (r = 0.83). In other words, animals with frontally‐placed eyes and, therefore, a high degree of binocular overlap, are better able to localize sounds in front of them than are animals whose vision is directed more to the side. However, whether this correlation indicates a close link between sound localization and visual localization or whether it simply indicates an increased interest in frontally‐occurring events on the part of an animal remains to be determined. [Work supported by NSF and NIH].
FREE

Sound localization and high‐frequency hearing in horses (A)

Henry E. Heffner and Rickye S. Heffner

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S42-S42 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The ability of mammals to hear high‐frequency sounds has often been attributed to the need to use binaural intensity differences (ΔI to localize sound [e.g., R. S. Heffner and H. E. Heffner, J. Comp. Physiol. Psychol. 96, 926–944 (1982)]. However, this explanation does not seem to account for the ability of horses to hear high‐frequency sounds. Specifically, while horses are able to localize low‐frequency tones, they are unable to localize tones above 1 kHz even though they can hear up to 35 kHz. These results suggest that while they can use interaural phase or time differences (Δt) to localize sound, they lack the ability to use the binaural ΔI cue. However, localization tests using filtered noise and sound sources located off to the side indicate that horses use pinna cues to localize sound and rely heavily on the high‐frequency content of a sound in order to prevent front‐back reversals. It appears, then, that horses have lost the ability to use binaural ΔI and rely primarily on binaural Δt and pinna cues in order to localize sound. Furthermore, since it seems unlikely that horses engage in ultrasonic communication, it apepars that they have evolved high‐frequency hearing primarily in response to the need to use pinna cues to localize sound. [Work supported by NSF and NIH.]
FREE

Discrimination of stationary and revolving targets by the FM bat, Eptesicus fuscus (A)

Weiping Zhang and Philip H.‐S. Jen

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S42-S42 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Four FM bats, Eptesicus fuscus, were trained to use their echolocation ability to discriminate a revolving target and a stationary target that were randomly and simultaneously placed in the directions of two of a three‐ramp platform. The bat‐to‐target distance ranged from 30 to 100 cm. The target was of semicircular shape with a radius of 16 mm and was made of thin copper plate of 0.05 mm. During the test, the frequency of a bat's approach to either target was recorded at each bat‐to‐target distance. Such a study revealed that a bat approached a revolving target more often than a stationary one. During the test, echolocation sounds emitted by three bats were recorded at bat‐to‐target distances of 40 and 80 cm. Analysis of these sounds revealed that there was no obvious difference in signal duration, interpulse intervals, or frequency contents among these sounds. A partial lesion was made electrolytically in the right hemisphere of the cerebellum of one bat. However, our study showed that such a partial lesion did not affect the bat's discrimination ability or the signal parameters of its emitted sounds. [Work supported by NSF 80‐07348 and USPH 1‐K04‐NS00433 to Philip H.‐S. Jen.]
FREE

Dynamic cues in binaural perception (A)

Stephen J. Bachorski and Richard M. Stern

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S42-S42 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
In recent years there has been renewed interest in the perception of stimuli with time‐varying interaural time delay, intensity difference, and correlation. The results of most of these studies indicate that the binaural system loses its ability to process time‐varying spatial images when the modulation rate of these interaural cues exceeds a few Hz. The position‐variable model of subjective lateral position [R. M. Stern and H. S. Colburn, J. Acoust. Soc. Am. 64, 127–140 (1978)] can be extended to accommodate stimuli with time‐varying interaural differences by forming time varying estimates of lateral position from interaural coincidences in auditory‐nerve activity, with greater weight applied to more recent neural events. The extended model is similar to the classical running crosscorrelation theory, but it is based on the crosscorrelation of hypothetical neural activity rather than the stimuli themselves. In this paper we present predictions of the model for the subjective laterality of time‐varying stimuli. We also compare predictions and data for discrimination and detection experiments, assuming that judgements are made on the basis of samples of the perceived lateral position and that performance is limited by the intrinsic variability of auditory‐nerve activity. [Supported by NIH.]
FREE

Velocity thresholds for simulated moving auditory signals (A)

D. Wesley Grantham

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S42-S43 (1983); (2 pages)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
An experiment was conducted to determine the auditory system's sensitivity to simulated movement of acoustic events in the horizontal plane. Movement was simulated by dynamically varying both the interaural time and intensity differences of waveforms presented dichotically over headphones. Stimuli were pure tones of 250, 500, 1000, or 2000 Hz. Durations varied from 100–500 ms; overall level was 83 dB SPL. In a two‐interval forced‐choice procedure subjects selected which of two tones was the “moving” tone. One of the two intervals contained a stationary signal. The other interval contained a single, left‐to‐right sweep of the same duration as the stationary signal; its velocity was varied in an adaptive procedure to track threshold. For 500‐ms stimuli thresholds were 10–15 deg/s for the three lower frequencies tested and about 40 deg/s for the 2000‐Hz signal. As stimulus duration decreased, thresholds increased, but not in such a way that “distance traveled” remained constant. At all durations tested, performance remained significantly worse at 2000 Hz than at the lower three frequencies. The best thresholds in this experiment were about two orders of magnitude greater than velocity thresholds determined for the visual system. [Work supported by NSF.]
FREE

Masking‐level differences for trains of clicks (A)

R. H. Dye and W. A. Yost

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The detectability of masked click trains was measured under homophasic (NoSo) and anitphasic (NoSπ) conditions as a function of the number of clicks (n = 1,2,4,8,16,32) in the train and the interclick interval (ICI = 2,5,10 ms) between the clicks. The clicks were bandpass filtered at 2 kHz and presented against broadband noise (5 kHz, low pass). The 3‐dB decline per doubling of duration usually found for antiphasic conditions [e.g., D. McFadden and A. D. Sharpley, J. Acoust. Soc. Am. 52, 574–576 (1972)] can be accounted for on the basis of energy detection or on the basis of optimal integration of samples of interaural differences of time and intensity between the S + N resultants at the two ears. The purpose of the present study was to measure MLDs under conditions for which optimal integration of interaural cues does not occur (short ICIs). Our results show that the slopes of the threshold versus n functions do not change with ICI, with the MLD remaining nearly constant across conditions. From this we conclude that the decline in threshold with duration (or n) for NoSπ is most consistent with energy detection and cannot easily be accounted for on the basis of integration of samples of interaural differences.
FREE

Detection of interaural differences of intensity in trains of filtered clicks (A)

R. H. Dye

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Threshold values of interaural differences of intensity (Δ IDI) were measured as a function of the number of clicks(n) and interclick interval (ICI = 1,2,5,10 ms) for trains of clicks that were bandpass filtered at either 4000 or 2000 Hz. Data were also gathered for trains whose clicks alternated between 4000 and 2000 Hz. The log‐log plots of Δ IDI (in dB) vs, n are quite similar for the single‐band and alternating‐band conditions, all showing shallower slopes at shorter ICIs. Furthermore, the slopes at a given ICI are quite similar across filtering conditions. These data are discussed in terms of possible mechanisms of binaural integration across bands of frequency.
FREE

Bandwidth of three‐element patterns and its effect on relative ear advantages (A)

Judith L. Lauter

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Since the earliest use of dichotic listening to measure performance differences in the two ears, the question of the influence of sound characteristics on the observed ear advantages (EA's) has been of central concern. In recent experiments studying the interactions between individual differences and sound characteristics, preliminary evidence for the importance of such characteristics as event timing, multi‐dimensional temporal changes, and bandwidth has been found. We have designed a stimulus set for studying the effect of three‐element pattern bandwidth on relative ear advantages. Three‐element patterns‐(6AFC), some made with filtered noise bursts, others with complex tones, have been tested on a number of subjects, for identification with contralateral interference [cf. J. L. Lauter, J. Acoust. Soc. Am. Suppl. 69, S22 (1982)]. Patterns or relative ear advantages indicate that as bandwidth in the patterns increases (e.g., comparing patterns made with tenth‐octave noise bands versus patterns of third‐octave noise bands), performance increasingly favors the right ear. It is suggested that this sensitivity of ear differences to stimulus bandwidth may contribute to the ear advantages observed for some speech sounds.
FREE

Dichotic temporal order judgment for long duration stimuli differing in stimulus microstructure and intensity (A)

L. F. Hughes, C. J. Miller, and E. Rafferty

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Temporal order judgments were determined for dichotically presented speech and speech‐eveloped noise stimuli. Stimulus onset asymmetries of 3, 6, 9, 20, 40, and 60 ms were factorially combined with intensity disparities between the ears of 0, 4, 8, and 16 dB. Naive subjects were instructed to indicate which ear was stimulated first. Hit and false alarm rates were obtained for each subject in each condition. Results contrasted with published nonmonotonic data (H. Babkoff, Percept. and Psychophys. 27, 273–275 (1980)], in that the difference between the normal deviates for hit and false alarm rates was a monotonic function of stimulus onset asychrony regardless of intensity desparity or stimulus type. The data were further analyzed in terms of the type of stimulus used, intensity imbalances between channels, ear differences, and stimulus onset asynchrony. Results will be discussed in terms of sensitivity and PSE measures for the foregoing factors.
FREE

An ear asymmetry in learning gap detection (A)

R. Efron, E. W. Yund, and D. Nichols‐Mello

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Gap detection performance was tested in each ear of 56 normal hearing subjects using 300 ms wide‐band (200–4000 Hz) unfrozen noise bursts. No ear asymmetry was observed in the gap detection thresholds. In subsequent studies of individual subjects in which the same noise burst was used in all trial (frozen noise) a progressive improvement in gap detection threshold was observed over a 20‐day period for both ears. Over the 20‐day period, however, a highly significant ear difference was observed in the learning curves of the two ears despite the fact that the right and left ears were tested on alternate trials. The ear asymmetry in gap detection was not present in the first few days for two subjects but became progressively more obvious as testing proceeded. The third subject exhibited an ear asymmetry on the first day's block of trials which increased only slightly over the 20‐day period. The right‐left asymmetry in learning gap detection in frozen noise is difficult to explain without postulating some (asymmetrical) central processing mechanism.
FREE

Cued dichotic listening (A)

E. J. Carney, A. E. Carney, R. A. Chmiel, and L. K. Fitzsimmons

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S43-S43 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
A new dichotic paradigm, called cued dichotic listening, was developed in which subjects receive the monotic presentation of one member of a dichotic pair of syllables prior to the dichotic presentation of the stimulus pair. In this procedure, subjects receive maximum information about the stimuli in one ear, called the cued ear. During dichotic presentation of a pair, the subject must identify only the stimulus in the noncued ear. Stimuli were synthetic syllables composed of the stop consanants /p,t,k,b,d,g/ plus the vowel /ɑ/, arranged into 30 dichotic pairs. Subjects received cues in both left and right ears on successive runs. Right ear advantage (REA) was calculated by subtracting the left‐ear score (cued right ear) from the right‐ear score (cued left ear). Subjects also received a standard dichotic condition with no cueing. Results indicated that the REA was increased in the cued condition compared to the standard condition. Cueing the left ear improved right‐ear performance; cueing the right ear did not affect left‐ear performance compared to the standard condition. These results suggest changes in phonetic processing, rather than auditory or attentional factors, contribute more to the REA.
FREE

High‐freqeuncy pitch perception (A)

Edward M. Burns and Lawrence L. Feth

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The alleged absence of musical pitch information for pure‐tone frequencies above about 5 kHz is often cited as constituting evidence for temporal coding of pure‐tone pitch below 5 kHz. However, the experimental data on which this allegation is based are both meager and equivocal. In this study, pure‐tone pitch perception for frequencies above 10 kHz was investigated using three paradigms: open set melody recognition by naive observers, and melodic dictation and musical interval adjustment by musicians. The results indicate that significant musical‐pitch information is available for frequencies above 10 kHz, although it is severely degraded relative to information at low frequencies. We have also investigated another pitch phenomenon which is assumed to be temporally based, the pitch differences associated with amplitude differences between the two components of unresolved two‐component complex tones. This pitch information is also significant, but degraded, for frequencies above 10 kHz. The degree of degradation of both types of pitch information at high frequencies is consistent with the relative increase in pure‐tone frequency DL's at high frequencies and is thus not incompatible with certain temporal models. [Supported by NINCDS.]
FREE

Predicting frequency selectivity in forward masking from simultaneous masking (A)

Robert A. Lutfi and Doris J. Kistler

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Measures of frequency selectivity from forward masking indicate sharper tuning than those from simultaneous masking (Houtgast, 1974; Moore, 1978). We show that a simple relation between forward and simultaneous masking predicts this result. Consider the masking of a 10‐ms, sinusoidal signal of frequency fs = 2.0 kHz by a 200‐ms, 50‐Hz‐wide narrow‐band noise masker with center frequency fm. Let Df  =  fm − fs be the frequency interval between the signal and the masker, and let Dt  =  ts − tm be the time interval between their offsets. We may define the following three masking conditions: (1) on‐frequency forward, Dt = 15 ms, Df = 0 Hz, (2) off‐frequency simultaneous, Dt = 0 ms, Df = 200 Hz, and (3) off‐frequency forward, Dt = 15 ms, Df = 200 Hz. Masking functions (signal intensity at masked threshold versus masker intensity) were obtained in each of these conditions. Our preliminary data indicate that the off‐frequency forward masking function (F) is predicted reasonably well by the composite relation F = G(kH), where G is the on‐frequency forward masking function, H is the off‐frequency simultaneous masking function, and k is a constant. Predictions were equally as good for other values of Df, yielding the expected difference in tuning between simultaneous and forward measures.
FREE

Forward masking tuning curves with randomized masker frequencies (A)

B. R. Shelton and J. C. Booth

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Forward‐masking psychophysical tuning curves broaden as the signal level is increased, and the detection of components remote from the nominal signal frequency is one of the mechanisms proposed to account for the observation [D. M. Green, B. R. Shelton, M. C. Picardi, and E. R. Hafter, J. Acoust. Soc. Am. 69, 1758–1762 (1981)]. It is reasonable to assume that the effectiveness of such a strategy would be maximized in the situation where the same signal and masker frequency is uncertain from one trial to the next. Tuning curves were obtained in 250‐trial runs with maskers of 500, 750, 1000, 1250, and 1500 Hz either randomized from trial‐to‐trial or presented in five 50‐trial blocks. The signal was a 1000‐Hz tone of either 5 or 30 dB SL. The tuning curve broadened with the high signal level, but the randomization of masker frequency had little or no effect on the sharpness of tuning. Similar results have been reported for a simultaneous masking procedure [B. R. Glasberg, B. C. J. Moore, and R. A. Lufti, J. Acoust. Soc. Am. 72, 273–275 (1982)]. The data offer no support to the hypothesis that off‐frequency listening can account for the broadening of psychophysical tuning curves with increased signal level. [Work supported by NSERC].
FREE

Temporal and capacity limitations of auditory memory (A)

Charles S. Watson and David C. Foyle

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Certain limits of auditory memory were estimated in a parametric study using tonal patterns. In a same‐different task, seven listeners were presented patterns consisting of sequences of equal duration, 300 Hz to 3 KHz tones. A threshold tracking procedure was used to determine the number of tones for which constant‐duration patterns could be discriminated. Six pattern durations were investigated, 62.5 to 2000 ms. Seven types of pattern differences were used, including the interchange of component tones, the frequency change of a component tone, replacement of a component tone by a gap, and a change in the temporal position of a gap. For patterns that differ by the presence of gaps, or in gap position, performance is limited by the duration of a just‐detectable gap. For discriminations in which the pitch of each component must be processed, there are no clearly defined optimal durations for whole patterns or for pattern components. These results are discussed in terms of the hypothesis that certain types of auditory pattern discrimination are limited by channel capacity (in terms of components per unit time) while others are determined by spectral or temporal resolving power. [Work supported by NIH/NINCDS.]
FREE

Speech discrimination ability and its relation to psychophysical tuning curves (PTCs) (A)

P. G. Stelmachowicz, M. P. Gorga, W. Jesteadt, and J. Mort

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
PTCs were obtained from normal and hearing‐impaired listeners using a simultaneous masking paradigm. All impaired listeners presented fiat moderate sensorineural hearing losses with excellent (90%) speech discrimination ability (NU‐6) in quiet. Probe stimuli were presented at 10 dB SL for impaired listeners and were varied from 10–60 dB SL for normal subjects. PTCs were quantified in terms of Q10 and tip‐to‐tail intersect. Performance‐intensity functions for monosyllabic words were obtained as a function of signal‐to‐noise ratio for broadband and low‐pass (500 Hz) filtered noise. Normal listeners demonstrated a decrease in tip‐to‐tail intersect and an increase in Q10 with increasing probe level. Regardless of whether comparisons were made across constant SL or constant SPL, impaired listeners exhibited smaller tip‐to‐tail differences than normal subjects with less obvious changes noted in Q10. While speech discrimination performances in broadband noise was similar for both groups, performance in low‐pass noise was poorer for the impaired group. The significance of changes in PTC shape in the presence of hearing loss will be discussed.
FREE

Measurement of adaptation effects using serial reaction times (A)

Thomas M. Goldman, Ernest M. Weiler, and James M. Davis

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S44 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
This investigation examined the use for a reaction time procedure to measure monaural auditory adaptation. Several studies using reaction times to a pure tone have demonstrated significant increases in latency after 7‐min duration of a continued tone. In the present study, serial reaction times to tonal onset (400 Hz) were measured at regular intervals while the subjects were stimulated with a continuous (500 Hz) pure tone for 3 min. Although mean values indicate a change of response latency between baseline at 400 Hz and the first test in the presence of 500 Hz, there is no evidence of further significant change in latency. No evidence was found for cumulative adaptation of latency times.
FREE

A functional adaptivity basis for the mechano‐neural transduction process in hearing (A)

Roger A. Adelman and Ernest M. Weiler

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S44-S45 (1983); (2 pages)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
A model for the mechano‐neural transduction process which includes an adaptivity or tuning mechanism is presented. The adaptivity system is predicted on the role of inner hair cells as primary transducers whose action potential thresholds are modified by neighboring outer hair cells. The proposed mechanism finds basis in the neural anatomy associated with these structures and is consistent with the predominance of efferent terminations on outer hair cells and the predominance of afferent origins from inner hair cells. The adaptivity is functionally consistent with phychoacoustic demonstration of pitch and loudness discrimination as well as adaptive and fatigue behavior.
FREE

Vasomotor response to pure tones using multifinger photoplethysmography (A)

Eileen Ayres Sarb, Ruth Mojdehi, and Ernest M. Weiler

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S45-S45 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Changes in digit pulse volume were measured in ten normal hearing, awake adults with a multifinger photocell ploethysmograph (Wasserman et al. 1979). Pure tone stimuli were presented at 500, 1000, and 2000 Hz to determine the threshold required for a verifiable vasomotor response. Results yielded a mean value across frequencies of 32.75 dB SL with a range of 0 to 85 dB relative to voluntary auditory threshold. There was a significant interaction between trials and frequency. The average was comparable to Mojdehi (1980) who reported values equal to 38.18 dB SL for white noise. The pure tone analysis required approximately 2 h per subject. The authors question the practical usefulness of extending the original white noise screening to pure tone assessment.
FREE

Stability of earplug attenuation over time (A)

Larry E. Humes and Jayne B. Ahlstrom

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S45-S45 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The real‐ear‐attenuation‐at‐threshold (REAT) procedure was used to measure the stability of the sound attenuation provided by earplugs over time. Two earplugs were evaluated (E‐A‐R plug and V‐51 plug) on six‐eight normal‐hearing young adults. Attenuation was measured at 500, 1000, 4000, and 8000 Hz following “use” of the protector for 1, 7, 14, 28, 56, and 84 days. “Use” of the protector consisted of insertion of the earplug for a period of 5 min, repeated five times daily. The E‐A‐R plug demonstrated greater attenuation on the initial day of testing, prior to repeated use. The E‐A‐R protector, however, exhibited a 10–15 dB decrease in attenuation at all frequencies at the end of the test period while the V‐51 plug demonstrated stable attenuation throughout the 84‐day period. Consequently, the E‐A‐R plug provided greater attenuation than the V‐51 plug following short periods of use (⩽28 days) while the V‐51 plug offered more attenuation following longer periods of use (56 and 84 days). [Work supported by Grant 5‐R01‐OH00895 from NIOSH.]
FREE

Real‐ear calibration of circumaural earphones (A)

R. C. Bilger, M. L. Matthies, M. Yuchtman, and J. Molloy

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S45-S45 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The absence of an acceptable calibration technique for circumaural earphones has prevented their use in audiometry in spite of their many advantages (e.g., less stringent control of background noise). A calibration of circumaural earphones (Pedersen) based on direct reading of sound pressure level under the phones is reported here. Measures were obtained for the occluded ear, a mid‐concha placement, and a mid‐canal placement of an electret microphone (Knowles, 1759a) in response to third‐octave bands of noise (100–10 000 Hz). Occluded‐ear measures were obtained systematically for six adult, male and six adult, female subjects. In addition, thresholds for the 21 bands of noise were obtained for the Pedersens and for TDH‐39 receivers mounted in MX 41/AR cushions. Analysis of acoustic data show an interactive effect of sex and frequency that is smaller than 3 dB and is presumably related to pinna size. The correlations between acoustic and behavioral data were acceptably high. Interpreted in terms of Shaw's extensive measures of sound pressure in an around the human ear, these data provide an acceptable acoustic calibration of these earphones. [Work supported by NINCDS.]
FREE

A comparison of detection thresholds obtained with forced‐choice procedures and with a standard clinical procedure (A)

Lynne Marshall and Walt Jesteadt

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S45-S45 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Detection thresholds, psychometric functions, and response criteria were measured for groups of younger and older normal and hearing‐impared adults (total N = 72). Detection thresholds were obtained at 500 and 4000 Hz using a standard clinical procedure and a two‐interval, forced‐choice (2IFC) adaptive procedure. A measure of response bias was obtained using a yes‐no procedure. Psychometric functions were obtained for all three procedures. The 2IFC adaptive thresholds were approximately 7 dB lower than standard clinical thresholds for all four groups of listeners. Data from the yes‐no procedure indicated that all four groups were equally conservative. There was no correlation between the magnitude of the difference between adaptive and clinical thresholds and the degree of response bias. Psychometric functions for the forced‐choice procedures were generally shallower than those for the standard clinical procedure and were shifted several dB to the left. Criterion effects do not appear to account for the difference between these psychometric functions or the difference between adaptive and clinical thresholds. [Work supported by NIH and UCR‐UNO.]
FREE

Stepwise dependence of binaural loudness summation of interaural phase (A)

B. E. Mulligan and D. P. Gleisner

J. Acoust. Soc. Am. Volume 73, Issue S1, pp. S45-S45 (1983); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Findings reported previously [B. E. Mulligan and L. S. Goodman, J. Acoust. Soc. Am. Suppl. 1 70, S106 (1981)] indicated a stepwise dependence of binaural loudness on interaural phase for 250‐Hz tones presented in “quiet.” The step in loudness {for both monaural‐binaural pairs of tones) was found to occur in the vicinity of the Hornbostel‐Wertheimer constant (± 59°) on each side. Utilizing the same procedure, the present research extends these findings to tone frequencies of 500, 650, 1000, 1200, and 1400 Hz. Again the step was found to occur in the region of the Hornbostel‐Wertheimer constant for 500‐ and 650‐Hz tones (± 117° and ± 153°). However for frequencies of 1000, 1200, and 1400 Hz, the steps occurred at approximately ± 125°, ± 78°, and ± 31° respectively. These values corespond to the natural limits of confusion‐free zones for tones of these frequencies. This suggests that binaural loudness may reflect a summative process which differentiates between tonal signals originating at angles of azimuth within and without confusion zones.
Return to All Sections
Close

Home Publications Meetings Contact ASA Site Map Back to Top

Copyright © Acoustical Society of America

close