Intelligibility of Modified Speech for Young Listeners With Normal and Impaired Hearing Exposure to modified speech has been shown to benefit children with languagelearning impairments with respect to their language skills (M. M. Merzenich et al., 1998; P. Tallal et al., 1996). In the study by Tallal and colleagues, the speech modification consisted of both slowing down and amplifying fast, transitional elements ... Research Article
Research Article  |   October 01, 2002
Intelligibility of Modified Speech for Young Listeners With Normal and Impaired Hearing
 
Author Affiliations & Notes
  • Rosalie M. Uchanski, PhD
    Central Institute for the Deaf Saint Louis, MO
  • Ann E. Geers
    Central Institute for the Deaf Saint Louis, MO
  • Athanassios Protopapas
    Scientific Learning Corporation Berkeley, CA
  • Contact author: Rosalie M. Uchanski, PhD, Central Institute for the Deaf, 4560 Clayton Avenue, Saint Louis, MO 63110. E-mail: ruchanski@cid.wustl.edu
Article Information
Speech, Voice & Prosodic Disorders / Hearing Disorders / Hearing / Research Articles
Research Article   |   October 01, 2002
Intelligibility of Modified Speech for Young Listeners With Normal and Impaired Hearing
Journal of Speech, Language, and Hearing Research, October 2002, Vol. 45, 1027-1038. doi:10.1044/1092-4388(2002/083)
History: Received November 2, 2000 , Accepted March 21, 2002
 
Journal of Speech, Language, and Hearing Research, October 2002, Vol. 45, 1027-1038. doi:10.1044/1092-4388(2002/083)
History: Received November 2, 2000; Accepted March 21, 2002
Web of Science® Times Cited: 12

Exposure to modified speech has been shown to benefit children with languagelearning impairments with respect to their language skills (M. M. Merzenich et al., 1998; P. Tallal et al., 1996). In the study by Tallal and colleagues, the speech modification consisted of both slowing down and amplifying fast, transitional elements of speech. In this study, we examined whether the benefits of modified speech could be extended to provide intelligibility improvements for children with severe-to-profound hearing impairment who wear sensory aids. In addition, the separate effects on intelligibility of slowing down and amplifying speech were evaluated.

Two groups of listeners were employed: 8 severe-to-profoundly hearingimpaired children and 5 children with normal hearing. Four speech-processing conditions were tested: (1) natural, unprocessed speech; (2) envelope-amplified speech; (3) slowed speech; and (4) both slowed and envelope-amplified speech. For each condition, three types of speech materials were used: words in sentences, isolated words, and syllable contrasts. To degrade the performance of the normal-hearing children, all testing was completed with a noise background.

Results from the hearing-impaired children showed that all varieties of modified speech yielded either equivalent or poorer intelligibility than unprocessed speech. For words in sentences and isolated words, the slowing-down of speech had no effect on intelligibility scores whereas envelope amplification, both alone and combined with slowing-down, yielded significantly lower scores. Intelligibility results from normal-hearing children listening in noise were somewhat similar to those from hearing-impaired children. For isolated words, the slowing-down of speech had no effect on intelligibility whereas envelope amplification degraded intelligibility. For both subject groups, speech processing had no statistically significant effect on syllable discrimination. In summary, without extensive exposure to the speech processing conditions, children with impaired hearing and children with normal hearing listening in noise received no intelligibility advantage from either slowed speech or envelope-amplified speech.

Acknowledgments
This work was supported by an anonymous, private foundation. The authors acknowledge and thank Scientific Learning Corporation for its cooperation and generosity in processing the original speech materials.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access