Effect of Dual-Carrier Processing on the Intelligibility of Concurrent Vocoded Sentences Purpose The goal of this study was to examine the role of carrier cues in sound source segregation and the possibility to enhance the intelligibility of 2 sentences presented simultaneously. Dual-carrier (DC) processing (Apoux, Youngdahl, Yoho, & Healy, 2015) was used to introduce synthetic carrier cues in vocoded speech. ... Research Article
Research Article  |   November 08, 2018
Effect of Dual-Carrier Processing on the Intelligibility of Concurrent Vocoded Sentences
 
Author Affiliations & Notes
  • Frédéric Apoux
    Department of Otolaryngology, The Ohio State University Wexner Medical Center, Columbus
  • Brittney L. Carter
    Department of Speech and Hearing Science, The Ohio State University, Columbus
  • Eric W. Healy
    Department of Speech and Hearing Science, The Ohio State University, Columbus
  • Disclosure: The authors have declared that no competing interests existed at the time of publication.
    Disclosure: The authors have declared that no competing interests existed at the time of publication. ×
  • Correspondence to Frédéric Apoux: fred.apoux@gmail.com
  • Editor-in-Chief: Frederick (Erick) Gallun
    Editor-in-Chief: Frederick (Erick) Gallun×
  • Editor: Jennifer Lentz
    Editor: Jennifer Lentz×
Article Information
Speech, Voice & Prosodic Disorders / Hearing / Research Articles
Research Article   |   November 08, 2018
Effect of Dual-Carrier Processing on the Intelligibility of Concurrent Vocoded Sentences
Journal of Speech, Language, and Hearing Research, November 2018, Vol. 61, 2804-2813. doi:10.1044/2018_JSLHR-H-17-0234
History: Received June 16, 2017 , Revised December 5, 2017 , Accepted June 11, 2018
 
Journal of Speech, Language, and Hearing Research, November 2018, Vol. 61, 2804-2813. doi:10.1044/2018_JSLHR-H-17-0234
History: Received June 16, 2017; Revised December 5, 2017; Accepted June 11, 2018

Purpose The goal of this study was to examine the role of carrier cues in sound source segregation and the possibility to enhance the intelligibility of 2 sentences presented simultaneously. Dual-carrier (DC) processing (Apoux, Youngdahl, Yoho, & Healy, 2015) was used to introduce synthetic carrier cues in vocoded speech.

Method Listeners with normal hearing heard sentences processed either with a DC or with a traditional single-carrier (SC) vocoder. One group was asked to repeat both sentences in a sentence pair (Experiment 1). The other group was asked to repeat only 1 sentence of the pair and was provided additional segregation cues involving onset asynchrony (Experiment 2).

Results Both experiments showed that not only is the “target” sentence more intelligible in DC compared with SC, but the “background” sentence intelligibility is equally enhanced. The participants did not benefit from the additional segregation cues.

Conclusions The data showed a clear benefit of using a distinct carrier to convey each sentence (i.e., DC processing). Accordingly, the poor speech intelligibility in noise typically observed with SC-vocoded speech may be partly attributed to the envelope of independent sound sources sharing the same carrier. Moreover, this work suggests that noise reduction may not be the only viable option to improve speech intelligibility in noise for users of cochlear implants. Alternative approaches aimed at enhancing sound source segregation such as DC processing may help to improve speech intelligibility while preserving and enhancing the background.

Acknowledgments
Execution of this study was supported in part by R01 DC08594, and article preparation was supported in part by R01 DC15521, both to author E. W. H.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access