Exploring the Limits of Frequency Lowering PurposeThis study examined how frequency lowering affected sentence intelligibility and quality for adults with postlingually acquired, mild-to-moderate hearing loss.MethodListeners included adults aged 60–92 years with sloping sensorineural hearing loss and a control group of similarly aged adults with normal hearing. Sentences were presented in quiet and babble at a range ... Article
Article  |   October 01, 2013
Exploring the Limits of Frequency Lowering
 
Author Affiliations & Notes
  • Pamela E. Souza
    Northwestern University, Evanston, IL
  • Kathryn H. Arehart
    University of Colorado, Boulder
  • James M. Kates
    University of Colorado, Boulder
  • Naomi B. H. Croghan
    University of Colorado, Boulder
  • Namita Gehani
    Northwestern University, Evanston, IL
  • Correspondence to Pamela E. Souza: p-souza@northwestern.edu
  • Editor: Jody Kreiman
    Editor: Jody Kreiman×
  • Associate Editor: Andrea Pittman
    Associate Editor: Andrea Pittman×
Article Information
Speech, Voice & Prosodic Disorders / Hearing Disorders / Hearing Aids, Cochlear Implants & Assistive Technology / Speech, Voice & Prosody / Hearing
Article   |   October 01, 2013
Exploring the Limits of Frequency Lowering
Journal of Speech, Language, and Hearing Research, October 2013, Vol. 56, 1349-1363. doi:10.1044/1092-4388(2013/12-0151)
History: Received May 7, 2012 , Revised September 18, 2012 , Accepted January 9, 2013
 
Journal of Speech, Language, and Hearing Research, October 2013, Vol. 56, 1349-1363. doi:10.1044/1092-4388(2013/12-0151)
History: Received May 7, 2012; Revised September 18, 2012; Accepted January 9, 2013
Web of Science® Times Cited: 15

PurposeThis study examined how frequency lowering affected sentence intelligibility and quality for adults with postlingually acquired, mild-to-moderate hearing loss.

MethodListeners included adults aged 60–92 years with sloping sensorineural hearing loss and a control group of similarly aged adults with normal hearing. Sentences were presented in quiet and babble at a range of signal-to-noise ratios. Intelligibility and quality were measured with varying amounts of frequency lowering, implemented using a form of frequency compression.

ResultsModerate amounts of compression, particularly with high cutoff frequencies, had minimal effects on sentence intelligibility. Listeners with the greatest high-frequency hearing loss showed the greatest benefit. Sentence intelligibility decreased with more compression. Listeners were more affected by a given set of parameters in noise than in quiet. In quiet, any amount of compression resulted in lower speech quality for most listeners, with the greatest degradation for listeners with better high-frequency hearing. Quality ratings were lower with background noise, and in noise, the effect of changing compression parameters was small.

ConclusionsThe benefits of frequency lowering in adults were affected by the compression parameters as well as individual hearing thresholds. The data are consistent with the idea that frequency lowering can be viewed in terms of improved audibility versus increased distortion trade-off.

Acknowledgments
We thank Peggy Nelson for sharing speech materials and Eric Hoover and Ramesh Muralimanohar for assistance with calibration. This work was supported by National Institutes of Health Grants R01 DC60014 (P. Souza) and R01 DC012289 (P. Souza/K. Arehart) and by a grant to the University of Colorado by GN ReSound (K. Arehart).
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access