Affordable Access

Publisher Website

Voice Discrimination in Quiet and in Background Noise by Simulated and Real Cochlear Implant Users.

Authors
  • Levin, Michal1
  • Zaltz, Yael1, 2
  • 1 Department of Communication Disorders, The Stanley Steyer School of Health Professions, Faculty of Medicine, Tel Aviv University, Israel. , (Israel)
  • 2 Sagol School of Neuroscience, Tel Aviv University, Israel. , (Israel)
Type
Published Article
Journal
Journal of speech, language, and hearing research : JSLHR
Publication Date
Dec 11, 2023
Volume
66
Issue
12
Pages
5169–5186
Identifiers
DOI: 10.1044/2023_JSLHR-23-00019
PMID: 37992412
Source
Medline
Language
English
License
Unknown

Abstract

Cochlear implant (CI) users demonstrate poor voice discrimination (VD) in quiet conditions based on the speaker's fundamental frequency (fo) and formant frequencies (i.e., vocal-tract length [VTL]). Our purpose was to examine the effect of background noise at levels that allow good speech recognition thresholds (SRTs) on VD via acoustic CI simulations and CI hearing. Forty-eight normal-hearing (NH) listeners who listened via noise-excited (n = 20) or sinewave (n = 28) vocoders and 10 prelingually deaf CI users (i.e., whose hearing loss began before language acquisition) participated in the study. First, the signal-to-noise ratio (SNR) that yields 70.7% correct SRT was assessed using an adaptive sentence-in-noise test. Next, the CI simulation listeners performed 12 adaptive VDs: six in quiet conditions, two with each cue (fo, VTL, fo + VTL), and six amid speech-shaped noise. The CI participants performed six VDs: one with each cue, in quiet and amid noise. SNR at VD testing was 5 dB higher than the individual's SRT in noise (SRTn +5 dB). Results showed the following: (a) Better VD was achieved via the noise-excited than the sinewave vocoder, with the noise-excited vocoder better mimicking CI VD; (b) background noise had a limited negative effect on VD, only for the CI simulation listeners; and (c) there was a significant association between SNR at testing and VTL VD only for the CI simulation listeners. For NH listeners who listen to CI simulations, noise that allows good SRT can nevertheless impede VD, probably because VD depends more on bottom-up sensory processing. Conversely, for prelingually deaf CI users, noise that allows good SRT hardly affects VD, suggesting that they rely strongly on bottom-up processing for both VD and speech recognition.

Report this publication

Statistics

Seen <100 times