• 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

Apr 1985

Volume 77, Issue S1, pp. S1-S108

Return to All Sections
back to top
RSS Feeds
back to top Session DD. Physiological Acoustics IV: Auditory Evoked and Steady‐State Responses
Contributed Papers
FREE

Can ABR latency measures predict psychoacoustic performance? (A)

Sheila V. Stager and Ted L. Langford

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S64-S65 (1985); (2 pages)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The possibility of a predictive relationship between an electrophysiological measure—the auditory brainstem response—and a psychoacoustic measure of the ability to discriminate interaural level differences was explored. Thirty‐seven subjects, from 15 to 51 years, participated in both parts of the study. Brainstem responses were simultaneously recorded in the vertical and horizontal derivations using both condensation and rare‐faction clicks at a rate of 21.1 per second at 70 dB nHL. Six measures, the absolute latencies of waves I, III, and V and their interpeak durations, were determined. A “same/different” procedure was used to measure the discriminability of noise bursts with interaural level differences of 1.5, 3, and 6 dB. The interaural difference which produced a 75% level of performance was determined from the resulting psychometric functions, and used in subsequent calculations. A predictive relationship was assumed if a significant linear relationship existed between any latency measure and psychoacoustic performance. Age and sex were included as variables. Fourteen ABR latency measures, primarily absolute latency measures, predicted or were predicted by performance on interaural level discrimination. Ear of stimulation was a key parameter of the predicted latencies. [Work supported in part by NIH grant #NS16396.]
FREE

Evoked potentials: An automated threshold‐tracking procedure using an objective detection criterion (A)

William A. Ahroon, Samuel S. Saunders, Sally A. Arnold, and Richard J. Salvi

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S65 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The estimation of auditory sensitivity or “threshold” using various evoked‐potentials generally has been made by visually inspecting a series of waveforms obtained over a range of stimulus intensities. As intensity is decreased, the object waveform gradually disappears into the background of neural activity and the experimenter/clinician must make some arbitrary decision about the intensity region in which this occurs (i.e., threshold). Difficulties can arise in making these judgments; waveform amplitudes may be unstable over time, different observers may have substantial biases which affect the threshold judgments or the range of data that is ultimately collected. This paper illustrates how a relatively simple quantitative technique (correlation) can be used to reliably estimate evoked‐potential thresholds in the chinchilla. Evoked potentials were recorded from chronic electrodes implanted in the inferior colliculus. Correlations among prestimulus and poststimulus waveforms were used by a computer‐automated threshold‐tracking procedure to increase or decrease stimulus intensity. The objective procedure yielded comparable results to visual threshold determinations by highly practiced observers. The practical aspects of using an automated threshold‐tracking procedure are discussed.
FREE

Auditory OFF and ON evoked potentials have different frequency‐ and intensity‐specific properties (A)

Kenneth R. Henry

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S65 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
An auditory brainstem response (ABR) can be elicited to both the onset and offset of a sufficiently long duration tone. In the laboratory mouse, the onset and offset ABR are similar enough in waveform and latencies to assume a similar source for these two measures. However, the shape of the visual detection level audiograms of onset and offset ABRs are quite different. Onset ABR threshold audiograms reflect behavioral audiograms, having their lowest thresholds at midfrequencies. By contrast, offset ABR thresholds from normally hearing CBA/J mice are highest at midfrequencies. Genetic factors can differentially affect these two responses. The slope and shapes of the onset and offset ABR amplitude input‐output functions also differ, as does the effect of frequency on these measures.
FREE

Individual differences in auditory evoked responses: Comparisons of between‐subject and within‐subject variability in brainstem and cortical waveforms (A)

Judith L. Lauter and Robert Loomis

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S65 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
Auditory evoked responses have been used for some time for diagnostic puposes. However, data regarding the range of normal variability have not been reported until recently. Published results have described variability across laboratories, across sessions within the same laboratory, and across subjects. However, although within‐subject variability is also of obvious importance for interpreting clinical findings, this source of evoked‐response variability has not been studied. An experiment was designed to study the normal between‐subject and within‐subject variability of AER amplitude and latency, comparing monaural versus binaural presentation, in several waveform peaks from brainstem to cortex. Results on monaural/binaural distinctions and other details of the responses show good agreement with earlier reports. In addition, observations on individual differences suggest that levels of auditory nervous system organization may be reflected in patterns of AER variability. [Work supported by NINCDS.]
FREE

Evoked response recovery functions using a “forward masking” paradigm (A)

Shalini Arehole, Richard J. Salvi, Samuel S. Saunders, and Roger P. Hamernik

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S65 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The amplitude of the evoked response was measured in a “forward masking” paradigm. Normal hearing chinchillas with electrodes implanted in the vicinity of inferior colliculus were used as subjects. A probe of 10‐ms duration was set at 10 dB above the evoked response threshold. The amplitude of the probe response was measured either in isolation or following a 100‐ms adaptor. The level of the adaptor required to reduce the amplitude of the probe response by 50% was measured over a range of adaptor‐probe interval in order to map out the recovery function. The adaptor and probe tone were at the same frequency and the recovery functions were measured at 500, 2000, 4000, and 8000 Hz. At short adaptor‐probe intervals, relatively low level adaptors were sufficient to reduce the probe response by 50%; however, as the interval between probe and adaptor increased, the level of the adaptor required to reduce the probe response by 50% increased significantly. The results of the present study will be discussed in relation to earlier physiological and psychophysical results. [Supported by NIH 1ROI‐NS1676 and NIOSH I‐ROI‐OH00364.]
FREE

Studies of the auditory steady‐state response I. Minute‐rhythms (A)

Scott Makeig, Robert Galambos, and David R. Stapells

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S65 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
A train of discrete stimuli (clicks or tonebursts) delivered to the ear at rates near 40 per second evokes a corresponding train of roughly sinusoidal brain potentials (the 40 Hz ERP, the high‐rates or steady‐state response, etc.). Since the response lasts as long as the stimulus train continues (minutes, hours) it may be used as an ongoing probe of changes within the auditory CNS. We have been studying both the spontaneous and event‐related modulations of the complex response (amplitude, phase) during behavioral experiments (threshold estimation, masking, vigilance, etc.). In resting subjects, quasirhythmic fluctuations in response amplitude and phase occur spontaneously, with periods of 20–120 s (“minute‐rhythms”). Amplitudes may vary by 100% or more, especially as the subject drifts into or out of sleep. We have also observed minute‐rhythms in responses to visual and tactile stimulation at similar repetition rates, and in concurrent measures of performance and EEG‐band amplitudes during a vigilance task. Evidently, minute‐rhythms are a natural feature of brain electrophysiology. [Work supported by NIH.]
FREE

Studies of the auditory steady‐state response II. Masking (A)

Robert Galambos, Scott Makeig, and David R. Stapells

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S65-S66 (1985); (2 pages)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
By definition, continuous wideband noise acts as a masker when it raises the threshold of a signal delivered to the contralateral ear. In our physiological studies the “signal” (a train of suprathreshold monaural clicks or tonepips) evokes brain potentials (the 40‐Hz or steady‐state response) that are continuously recorded and analyzed for amplitude and phase. When wideband noise is introduced into the contralateral ear at levels below that which raises the threshold of the signal, the evoked potential amplitudes typically drop monotonically with increase in noise intensity. Whether this physiological central suppression is related to “central masking” is unclear; certainly no perceptual correlate for it has yet been uncovered. [Work supported by NIH.]
FREE

Studies of the auditory steady‐state response III. Threshold estimation (A)

David R. Stapells, Scott Makeig, and Robert Galambos

J. Acoust. Soc. Am. Volume 77, Issue S1, pp. S66-S66 (1985); (1 page)

Online Publication Date: 12 Aug 2005

Full Text: | Download PDF

Show Abstract
The present studies investigate the use of “phase coherence” of steady‐state responses for the estimation of thresholds in normal hearing adults [Makeig and Galambos, J. Acoust. Soc. Am. Suppl. 1 74, S65 (1983)]. In the first study, rate‐series data (19/s–54/s) were obtained in ten subjects. Phase coherence was high in the 34–44/s range in all ten subjects, even when their maximum response amplitudes occurred at lower presentation rates. We then recorded responses at near‐threshold intensities (39.1/s rate) to two‐tone frequencies in six subjects and found significant responses (phase coherence, p < 0.01) within 6 dB of behavioral threshold at 500 Hz (mean 1.0 dB SL) and at 2000 Hz (mean 2.3 dB SL). The recording time necessary to obtain a significant response was then determined in ten subjects. At 25 dB SL, 17 of 20 recordings were significant within 50 s, and all 20 were significant within 7 min. At 10 dB SL, 29 of 40 recordings were significant within 4 min, and 38 of 40 were significant within 15 min (mean‐time‐to‐significance 2.5 min.) These results indicate that the use of steady‐state response phase coherence provides good estimates of threshold in adults within a practical recording time for audiometry. [Work supported by NIH.]
Return to All Sections
Close

Home Publications Meetings Contact ASA Site Map Back to Top

Copyright © Acoustical Society of America

close