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Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise

One of the putative functions of the medial olivocochlear (MOC) system is to enhance signal detection in noise. The objective of this study was to elucidate the role of the MOC system in speech perception in noise. In normal-hearing human listeners, we examined (1) the association between magnitude...

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Autores principales: Mishra, Srikanta K., Lutman, Mark E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3896402/
https://www.ncbi.nlm.nih.gov/pubmed/24465686
http://dx.doi.org/10.1371/journal.pone.0085756
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author Mishra, Srikanta K.
Lutman, Mark E.
author_facet Mishra, Srikanta K.
Lutman, Mark E.
author_sort Mishra, Srikanta K.
collection PubMed
description One of the putative functions of the medial olivocochlear (MOC) system is to enhance signal detection in noise. The objective of this study was to elucidate the role of the MOC system in speech perception in noise. In normal-hearing human listeners, we examined (1) the association between magnitude of MOC inhibition and speech-in-noise performance, and (2) the association between MOC inhibition and the amount of contralateral acoustic stimulation (CAS)-induced shift in speech-in-noise acuity. MOC reflex measurements in this study considered critical measurement issues overlooked in past work by: recording relatively low-level, linear click-evoked otoacoustic emissions (CEOAEs), adopting 6 dB signal-to-noise ratio (SNR) criteria, and computing normalized CEOAE differences. We found normalized index to be a stable measure of MOC inhibition (mean = 17.21%). MOC inhibition was not related to speech-in-noise performance measured without CAS. However, CAS in a speech-in-noise task caused an SNR(SP) enhancement (mean = 2.45 dB), and this improvement in speech-in-noise acuity was directly related to their MOC reflex assayed by CEOAEs. Individuals do not necessarily use the available MOC-unmasking characteristic while listening to speech in noise, or do not utilize unmasking to the extent that can be shown by artificial MOC activation. It may be the case that the MOC is not actually used under natural listening conditions and the higher auditory centers recruit MOC-mediated mechanisms only in specific listening conditions–those conditions remain to be investigated.
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spelling pubmed-38964022014-01-24 Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise Mishra, Srikanta K. Lutman, Mark E. PLoS One Research Article One of the putative functions of the medial olivocochlear (MOC) system is to enhance signal detection in noise. The objective of this study was to elucidate the role of the MOC system in speech perception in noise. In normal-hearing human listeners, we examined (1) the association between magnitude of MOC inhibition and speech-in-noise performance, and (2) the association between MOC inhibition and the amount of contralateral acoustic stimulation (CAS)-induced shift in speech-in-noise acuity. MOC reflex measurements in this study considered critical measurement issues overlooked in past work by: recording relatively low-level, linear click-evoked otoacoustic emissions (CEOAEs), adopting 6 dB signal-to-noise ratio (SNR) criteria, and computing normalized CEOAE differences. We found normalized index to be a stable measure of MOC inhibition (mean = 17.21%). MOC inhibition was not related to speech-in-noise performance measured without CAS. However, CAS in a speech-in-noise task caused an SNR(SP) enhancement (mean = 2.45 dB), and this improvement in speech-in-noise acuity was directly related to their MOC reflex assayed by CEOAEs. Individuals do not necessarily use the available MOC-unmasking characteristic while listening to speech in noise, or do not utilize unmasking to the extent that can be shown by artificial MOC activation. It may be the case that the MOC is not actually used under natural listening conditions and the higher auditory centers recruit MOC-mediated mechanisms only in specific listening conditions–those conditions remain to be investigated. Public Library of Science 2014-01-20 /pmc/articles/PMC3896402/ /pubmed/24465686 http://dx.doi.org/10.1371/journal.pone.0085756 Text en © 2014 Mishra, Lutman http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Mishra, Srikanta K.
Lutman, Mark E.
Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title_full Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title_fullStr Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title_full_unstemmed Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title_short Top-Down Influences of the Medial Olivocochlear Efferent System in Speech Perception in Noise
title_sort top-down influences of the medial olivocochlear efferent system in speech perception in noise
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3896402/
https://www.ncbi.nlm.nih.gov/pubmed/24465686
http://dx.doi.org/10.1371/journal.pone.0085756
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