Effect of Slow-Acting Wide Dynamic Range Compression on Measures of Intelligibility and Ratings of Speech Quality in Simulated-Loss Listeners The purpose of this study was twofold: (a) to determine the extent to which 4-channel, slow-acting wide dynamic range amplitude compression (WDRC) can counteract the perceptual effects of reduced auditory dynamic range and (b) to examine the relation between objective measures of speech intelligibility and categorical ratings of speech quality ... Research Article
Research Article  |   June 01, 2005
Effect of Slow-Acting Wide Dynamic Range Compression on Measures of Intelligibility and Ratings of Speech Quality in Simulated-Loss Listeners
 
Author Affiliations & Notes
  • Peninah S. Rosengard
    Harvard-MIT Division of Health Sciences and Technology and Massachusetts Institute of Technology
  • Karen L. Payton
    Massachusetts Institute of Technology and University of Massachusetts
  • Louis D. Braida
    Harvard-MIT Division of Health Sciences and Technology and Massachusetts Institute of Technology
  • Contact author: Peninah S. Rosengard, 50 Vassar Street, Cambridge, MA 02139. E-mail: peninah@mit.edu
Article Information
Speech, Voice & Prosodic Disorders / Hearing Disorders / Hearing Aids, Cochlear Implants & Assistive Technology / Hearing / Research Articles
Research Article   |   June 01, 2005
Effect of Slow-Acting Wide Dynamic Range Compression on Measures of Intelligibility and Ratings of Speech Quality in Simulated-Loss Listeners
Journal of Speech, Language, and Hearing Research, June 2005, Vol. 48, 702-714. doi:10.1044/1092-4388(2005/048)
History: Received October 21, 2004 , Accepted November 22, 2004
 
Journal of Speech, Language, and Hearing Research, June 2005, Vol. 48, 702-714. doi:10.1044/1092-4388(2005/048)
History: Received October 21, 2004; Accepted November 22, 2004
Web of Science® Times Cited: 5

The purpose of this study was twofold: (a) to determine the extent to which 4-channel, slow-acting wide dynamic range amplitude compression (WDRC) can counteract the perceptual effects of reduced auditory dynamic range and (b) to examine the relation between objective measures of speech intelligibility and categorical ratings of speech quality for sentences processed with slow-acting WDRC. Multiband expansion was used to simulate the effects of elevated thresholds and loudness recruitment in normal hearing listeners. While some previous studies have shown that WDRC can improve both speech intelligibility and quality, others have found no benefit. The current experiment shows that moderate amounts of compression can provide a small but significant improvement in speech intelligibility, relative to linear amplification, for simulated-loss listeners with small dynamic ranges (i.e., flat, moderate hearing loss). This benefit was found for speech at conversational levels, both in quiet and in a background of babble. Simulated-loss listeners with large dynamic ranges (i.e., sloping, mild-to-moderate hearing loss) did not show any improvement. Comparison of speech intelligibility scores and subjective ratings of intelligibility showed that listeners with simulated hearing loss could accurately judge the overall intelligibility of speech. However, in all listeners, ratings of pleasantness decreased as the compression ratio increased. These findings suggest that subjective measures of speech quality should be used in conjunction with either objective or subjective measures of speech intelligibility to ensure that participant-selected hearing aid parameters optimize both comfort and intelligibility.

Acknowledgments
This work was supported by National Institutes of Health Grants 5T32 DC 00038 and RO1 DC 00117. We wish to thank Joost M. Festen and Fan-Gang Zeng for helpful comments on a draft of the article.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access