Effects of noise on integration of acoustic and electric hearing within and across ears

Authors
Willis, Shelby 
Galvin, John J. 

Change log
Abstract

In bimodal listening, cochlear implant (CI) users combine electric hearing (EH) in one ear and acoustic hearing (AH) in the other ear. In electric-acoustic stimulation (EAS), CI users combine EH and AH in the same ear. In quiet, integration of EH and AH has been shown to be better with EAS, but with greater sensitivity to tonotopic mismatch in EH. The goal of the present study was to evaluate how external noise might affect integration of AH and EH within or across ears. Recognition of monosyllabic words was measured for normal-hearing subjects listening to simulations of unimodal (AH or EH alone), EAS, and bimodal listening in quiet and in speech-shaped steady noise (10 dB, 0 dB signal-to-noise ratio). The input/output frequency range for AH was 0.1–0.6 kHz. EH was simulated using an 8-channel noise vocoder. The output frequency range was 1.2–8.0 kHz to simulate a shallow insertion depth. The input frequency range was either matched (1.2–8.0 kHz) or mismatched (0.6–8.0 kHz) to the output frequency range; the mismatched input range maximized the amount of speech information, while the matched input resulted in some speech information loss. In quiet, tonotopic mismatch differently affected EAS and bimodal performance. In noise, EAS and bimodal performance was similarly affected by tonotopic mismatch. The data suggest that tonotopic mismatch may differently affect integration of EH and AH in quiet and in noise.

Publication Date
2020-10-15
Online Publication Date
Acceptance Date
2020-10-01
Keywords
Research Article, Biology and life sciences, Medicine and health sciences, Physical sciences, Social sciences, Engineering and technology
Journal Title
PLOS ONE
Journal ISSN
1932-6203
Volume Title
15
Publisher
Public Library of Science
Sponsorship
National Institute on Deafness and Other Communication Disorders (R01-DC016883)