An Examination of Speech Recognition in a Modulated Background and of Forward Masking in Younger and Older Listeners Purpose To compare speech intelligibility in the presence of a 10-Hz square-wave noise masker in younger and older listeners and to relate performance to recovery from forward masking. Method The signal-to-noise ratio required to achieve 50% sentence identification in the presence of a 10-Hz square-wave noise masker was ... Research Article
Research Article  |   August 01, 2007
An Examination of Speech Recognition in a Modulated Background and of Forward Masking in Younger and Older Listeners
 
Author Affiliations & Notes
  • René H. Gifford
    Arizona State University, Tempe
  • Sid P. Bacon
    Arizona State University, Tempe
  • Erica J. Williams
    Arizona State University, Tempe
  • Contact author: René H. Gifford, who is now at the Mayo Clinic, Department of Otorhinolaryngology, Eisenberg 2F, 200 First Street S.W., Rochester, MN 55905. E-mail: gifford.rene@mayo.edu.
Article Information
Hearing & Speech Perception / Hearing / Research Articles
Research Article   |   August 01, 2007
An Examination of Speech Recognition in a Modulated Background and of Forward Masking in Younger and Older Listeners
Journal of Speech, Language, and Hearing Research, August 2007, Vol. 50, 857-864. doi:10.1044/1092-4388(2007/060)
History: Received April 26, 2006 , Accepted December 7, 2006
 
Journal of Speech, Language, and Hearing Research, August 2007, Vol. 50, 857-864. doi:10.1044/1092-4388(2007/060)
History: Received April 26, 2006; Accepted December 7, 2006
Web of Science® Times Cited: 28

Purpose To compare speech intelligibility in the presence of a 10-Hz square-wave noise masker in younger and older listeners and to relate performance to recovery from forward masking.

Method The signal-to-noise ratio required to achieve 50% sentence identification in the presence of a 10-Hz square-wave noise masker was obtained for each of the 8 younger/older listener pairs. Listeners were matched according to their quiet thresholds for frequencies from 600 to 4800 Hz in octave steps. Forward masking was also measured in 2 younger/older threshold-matched groups for signal delays of 2–40 ms.

Results Older listeners typically required a significantly higher signal-to-noise ratio than younger listeners to achieve 50% correct sentence recognition. This effect may be understood in terms of increased forward-masked thresholds throughout the range of signal delays corresponding to the silent intervals in the modulated noise (e.g., <50 ms).

Conclusions Significant differences were observed between older and younger listeners on measures of both speech intelligibility in a modulated background and forward masking over a range of signal delays (0–40 ms). Age-related susceptibility to forward masking at relatively short delays may reflect a deficit in processing at a fairly central level (e.g., broader temporal windows or less efficient processing).

Acknowledgments
This work was supported by National Institute on Deafness and Other Communication Disorders Grants DC005085 (awarded to the first author) and DC01376 (awarded to the second author). A portion of the results was presented at the 2003 meeting of the American Auditory Society in Scottsdale, Arizona. We would like to thank the three anonymous reviewers for providing suggestions that greatly improved the manuscript.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access