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Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears

Spontaneous otoacoustic emissions (SOAEs) are weak sounds that emanate from the ears of tetrapods in the absence of acoustic stimulation. These emissions are an epiphenomenon of the inner ear's active process, which enhances the auditory system’s sensitivity to weak sounds, but their mechanism...

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Autores principales: Roongthumskul, Yuttana, Ó Maoiléidigh, Dáibhid, Hudspeth, A.J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Biophysical Society 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531668/
https://www.ncbi.nlm.nih.gov/pubmed/31010667
http://dx.doi.org/10.1016/j.bpj.2019.02.032
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author Roongthumskul, Yuttana
Ó Maoiléidigh, Dáibhid
Hudspeth, A.J.
author_facet Roongthumskul, Yuttana
Ó Maoiléidigh, Dáibhid
Hudspeth, A.J.
author_sort Roongthumskul, Yuttana
collection PubMed
description Spontaneous otoacoustic emissions (SOAEs) are weak sounds that emanate from the ears of tetrapods in the absence of acoustic stimulation. These emissions are an epiphenomenon of the inner ear's active process, which enhances the auditory system’s sensitivity to weak sounds, but their mechanism of production remains a matter of debate. We recorded SOAEs simultaneously from the two ears of the tokay gecko and found that binaural emissions could be strongly correlated: some emissions occurred at the same frequency in both ears and were highly synchronized. Suppression of the emissions in one ear often changed the amplitude or shifted the frequency of emissions in the other. Decreasing the frequency of emissions from one ear by lowering its temperature usually reduced the frequency of the contralateral emissions. To understand the relationship between binaural SOAEs, we developed a mathematical model of the eardrums as noisy nonlinear oscillators coupled by the air within an animal’s mouth. By according with the model, the results indicate that some SOAEs are generated bilaterally through acoustic coupling across the oral cavity. The model predicts that sound localization through the acoustic coupling between ears is influenced by the active processes of both ears.
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spelling pubmed-65316682020-05-21 Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears Roongthumskul, Yuttana Ó Maoiléidigh, Dáibhid Hudspeth, A.J. Biophys J Articles Spontaneous otoacoustic emissions (SOAEs) are weak sounds that emanate from the ears of tetrapods in the absence of acoustic stimulation. These emissions are an epiphenomenon of the inner ear's active process, which enhances the auditory system’s sensitivity to weak sounds, but their mechanism of production remains a matter of debate. We recorded SOAEs simultaneously from the two ears of the tokay gecko and found that binaural emissions could be strongly correlated: some emissions occurred at the same frequency in both ears and were highly synchronized. Suppression of the emissions in one ear often changed the amplitude or shifted the frequency of emissions in the other. Decreasing the frequency of emissions from one ear by lowering its temperature usually reduced the frequency of the contralateral emissions. To understand the relationship between binaural SOAEs, we developed a mathematical model of the eardrums as noisy nonlinear oscillators coupled by the air within an animal’s mouth. By according with the model, the results indicate that some SOAEs are generated bilaterally through acoustic coupling across the oral cavity. The model predicts that sound localization through the acoustic coupling between ears is influenced by the active processes of both ears. The Biophysical Society 2019-05-21 2019-04-02 /pmc/articles/PMC6531668/ /pubmed/31010667 http://dx.doi.org/10.1016/j.bpj.2019.02.032 Text en © 2019 Biophysical Society. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Articles
Roongthumskul, Yuttana
Ó Maoiléidigh, Dáibhid
Hudspeth, A.J.
Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title_full Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title_fullStr Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title_full_unstemmed Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title_short Bilateral Spontaneous Otoacoustic Emissions Show Coupling between Active Oscillators in the Two Ears
title_sort bilateral spontaneous otoacoustic emissions show coupling between active oscillators in the two ears
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531668/
https://www.ncbi.nlm.nih.gov/pubmed/31010667
http://dx.doi.org/10.1016/j.bpj.2019.02.032
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