A Component of Click-Evoked Otoacoustic Emissions Evoked due to Perturbation of Nonlinear Force in a Cochlear Model

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21230%2F24%3A00379580" target="_blank" >RIV/68407700:21230/24:00379580 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68407700:21340/24:00379580

Výsledek na webu

<a href="https://doi.org/10.5281/zenodo.13617624" target="_blank" >https://doi.org/10.5281/zenodo.13617624</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.5281/zenodo.13617624" target="_blank" >10.5281/zenodo.13617624</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A Component of Click-Evoked Otoacoustic Emissions Evoked due to Perturbation of Nonlinear Force in a Cochlear Model

Popis výsledku v původním jazyce

An analytic solution for stimulus-frequency otoacoustic emissions derived from the nonlinear cochlear model was presented at the Mechanics of Hearing meeting in 2022. Here, we describe how to use this solution for click-evoked otoacoustic emissions (CEOAEs) derived from the same model. The cochlear model is nonlinear because the feedback force, which is included in the model, is transformed by a sigmoidal nonlinearity proportional to the 2nd-order Boltzmann function. Our solution of the model equations extracts the nonlinear component of this feedback force and denotes this term the "nonlinear force". We showed that for SFOAEs the wavelets reflected from the irregularities perturb this nonlinear force. This perturbation yields an OAE component, which becomes significant as the simulated basilar membrane (BM) input/output (I/O) function approaches its compression knee (above about 20 dB SPL in the model). At low intensities (<20 dB SPL), SFOAEs and CEOAEs derived from the cochlear model are equivalent. As the intensity increases, the CEOAE amplitude increases and finally saturates. The CEOAE phase slope is intensity invariant. The amplitude saturation and phase intensity invariance of these CEOAEs is in contrast with the stimulus intensity effect on SFOAEs derived from the same model. For these SFOAEs, the component due to perturbation of the nonlinear force destructively interferes with the component due to linear reflection from irregularities. In addition, because the component due to perturbation of the nonlinear force has a slightly steeper phase slope than the component due to linear reflection, the amplitude fine-structure of SFOAE changes, and at some frequencies the SFOAE amplitude declines with increasing level. In other words, rather than just saturation as in CEOAEs, the SFOAE amplitude may decline and the SFOAE phase slope becomes shallower. For CEOAEs the component due to perturbation of the nonlinear force and the component due to linear reflection have similar phase slopes. These phase slopes become shallower as the intensity increases. However, the superposition of these two components yields CEOAE with a phase slope that is steeper than the phase slope of these two components. In conclusion, SFOAEs and CEOAEs derived from the same cochlear model differ as the intensity increases above the compression knee in the BM I/O function. The analytical solution can provide insight into the causes of the observed differences.

Název v anglickém jazyce

A Component of Click-Evoked Otoacoustic Emissions Evoked due to Perturbation of Nonlinear Force in a Cochlear Model

Popis výsledku anglicky

An analytic solution for stimulus-frequency otoacoustic emissions derived from the nonlinear cochlear model was presented at the Mechanics of Hearing meeting in 2022. Here, we describe how to use this solution for click-evoked otoacoustic emissions (CEOAEs) derived from the same model. The cochlear model is nonlinear because the feedback force, which is included in the model, is transformed by a sigmoidal nonlinearity proportional to the 2nd-order Boltzmann function. Our solution of the model equations extracts the nonlinear component of this feedback force and denotes this term the "nonlinear force". We showed that for SFOAEs the wavelets reflected from the irregularities perturb this nonlinear force. This perturbation yields an OAE component, which becomes significant as the simulated basilar membrane (BM) input/output (I/O) function approaches its compression knee (above about 20 dB SPL in the model). At low intensities (<20 dB SPL), SFOAEs and CEOAEs derived from the cochlear model are equivalent. As the intensity increases, the CEOAE amplitude increases and finally saturates. The CEOAE phase slope is intensity invariant. The amplitude saturation and phase intensity invariance of these CEOAEs is in contrast with the stimulus intensity effect on SFOAEs derived from the same model. For these SFOAEs, the component due to perturbation of the nonlinear force destructively interferes with the component due to linear reflection from irregularities. In addition, because the component due to perturbation of the nonlinear force has a slightly steeper phase slope than the component due to linear reflection, the amplitude fine-structure of SFOAE changes, and at some frequencies the SFOAE amplitude declines with increasing level. In other words, rather than just saturation as in CEOAEs, the SFOAE amplitude may decline and the SFOAE phase slope becomes shallower. For CEOAEs the component due to perturbation of the nonlinear force and the component due to linear reflection have similar phase slopes. These phase slopes become shallower as the intensity increases. However, the superposition of these two components yields CEOAE with a phase slope that is steeper than the phase slope of these two components. In conclusion, SFOAEs and CEOAEs derived from the same cochlear model differ as the intensity increases above the compression knee in the BM I/O function. The analytical solution can provide insight into the causes of the observed differences.

Druh

O - Ostatní výsledky

CEP obor

—

OECD FORD obor

10307 - Acoustics

Projekt

<a href="/cs/project/GC23-07621J" target="_blank" >GC23-07621J: Otoakustické emise v normální kochlee a při přetlaku v endolymfatickém prostoru kochley: modelování a experimenty</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů