Assessing Release-Time Options in a Two-Channel AGC Hearing Aid The purpose of this study was to determine whether different release times, as implemented in a commercial two-channel AGC hearing aid, would result in differing speech intelligibility performance, user preference, or use time. In experiment one, 14 subjects were fitted with a two-channel multi-memory AGC hearing aid. Four memories were ... Research Article
Research Article  |   March 01, 1997
Assessing Release-Time Options in a Two-Channel AGC Hearing Aid
 
Author Affiliations & Notes
  • Ruth A. Bentler, PhD
    Department of Speech Pathology and Audiology, 121B Wendell Johnson Speech & Hearing Center, The University of Iowa, Iowa City, IA 52242
  • John A. Nelson
    Department of Speech Pathology and Audiology, 121B Wendell Johnson Speech & Hearing Center, The University of Iowa, Iowa City, IA 52242
  • Corresponding author: e-mail: rbentler@wjshc-po.shc.uiowa.edu
  • Portions of this paper were presented at the American Speech-Language-Hearing Association Conventions in Anaheim, CA (1993) and New Orleans, LA (1994).
    Portions of this paper were presented at the American Speech-Language-Hearing Association Conventions in Anaheim, CA (1993) and New Orleans, LA (1994).×
Article Information
Hearing Aids, Cochlear Implants & Assistive Technology / Research Articles
Research Article   |   March 01, 1997
Assessing Release-Time Options in a Two-Channel AGC Hearing Aid
American Journal of Audiology, March 1997, Vol. 6, 43-51. doi:10.1044/1059-0889.0601.43
History: Received September 6, 1995 , Accepted March 26, 1996
 
American Journal of Audiology, March 1997, Vol. 6, 43-51. doi:10.1044/1059-0889.0601.43
History: Received September 6, 1995; Accepted March 26, 1996

The purpose of this study was to determine whether different release times, as implemented in a commercial two-channel AGC hearing aid, would result in differing speech intelligibility performance, user preference, or use time. In experiment one, 14 subjects were fitted with a two-channel multi-memory AGC hearing aid. Four memories were programmed to have identical frequency responses and output limitation characteristics. Only the release times were varied, with the low channel/high channel set as follows (in ms): 20/35, 20/150, 100/35, 500/7. Results obtained from the NST (+5 S/N), magnitude estimations of intelligibility, and data-logging of use time did not show any release-time pair to be superior to any other. In experiment two, 10 subjects participated in a forced-choice, paired-comparison procedure using the same release-time pairs from experiment one. Auditory stimuli consisted of three input levels, consisting of speech, speech in noise, and music. Results indicated no release-time pair to be superior in any listening condition. Results may be explained, in part, by the use of a curvilinear compression circuit and the milder hearing loss exhibited by the subjects. Future investigation of the effect of release-time variation should be carried out on circuits with adjustable compression parameters (and fixed compression ratios) with listeners exhibiting different degrees of hearing loss.

Acknowledgment
We gratefully acknowlege the assistance of Marlo Moeller in the data collection and subsequent analysis.
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