The University of Southampton
University of Southampton Institutional Repository

Fluid coupling and waves in the cochlea

Fluid coupling and waves in the cochlea
Fluid coupling and waves in the cochlea
The cochlea plays an important role in human hearing. Its basic function is to map sounds of different frequencies onto corresponding characteristic positions on the basilar membrane, BM. When sounds enter the fluid-filled cochlea, deflections of the BM occur due to pressure differences between the cochlear fluid chambers. These deflections propagate along the cochlea to a frequency-dependent characteristic position and then decay away rapidly. The mechanics of the cochlea are modelled using both analytic and numerical models. In this thesis, the passive response of the cochlea is analysed, corresponding to its behaviour at high sound levels, to study the fluid coupling and waves in the cochlea.

The fluid coupling is studied in 1D and 3D, uniform and non-uniform, uncoiled and coiled geometries, all with a passive basilar membrane. A ‘uniaxial model’, which is dependent on only a single dimension, is developed to represent the three-dimensional cochlea. The finite element method is also used to provide an independent check of the results from the analytic model.

Analytic methods are used to predict waves due to different mechanisms in the passive cochlea, such as 1D and 3D fluid coupling and longitudinal BM dynamics. The wave finite element, WFE, method is then used to decompose the results of a full finite element model of the coupled cochlea into wave components. Results show that apart from the conventional slow wave, other additional types of wave in the passive cochlea do not appear to play a dominant role in normal passive cochlear function.
Ni, Guangjian
f9f26088-dddb-42bc-8197-6027fc865f79
Ni, Guangjian
f9f26088-dddb-42bc-8197-6027fc865f79
Elliott, Stephen
721dc55c-8c3e-4895-b9c4-82f62abd3567

(2012) Fluid coupling and waves in the cochlea. University of Southampton, Faculty of Engineering and the Environment, Doctoral Thesis, 231pp.

Record type: Thesis (Doctoral)

Abstract

The cochlea plays an important role in human hearing. Its basic function is to map sounds of different frequencies onto corresponding characteristic positions on the basilar membrane, BM. When sounds enter the fluid-filled cochlea, deflections of the BM occur due to pressure differences between the cochlear fluid chambers. These deflections propagate along the cochlea to a frequency-dependent characteristic position and then decay away rapidly. The mechanics of the cochlea are modelled using both analytic and numerical models. In this thesis, the passive response of the cochlea is analysed, corresponding to its behaviour at high sound levels, to study the fluid coupling and waves in the cochlea.

The fluid coupling is studied in 1D and 3D, uniform and non-uniform, uncoiled and coiled geometries, all with a passive basilar membrane. A ‘uniaxial model’, which is dependent on only a single dimension, is developed to represent the three-dimensional cochlea. The finite element method is also used to provide an independent check of the results from the analytic model.

Analytic methods are used to predict waves due to different mechanisms in the passive cochlea, such as 1D and 3D fluid coupling and longitudinal BM dynamics. The wave finite element, WFE, method is then used to decompose the results of a full finite element model of the coupled cochlea into wave components. Results show that apart from the conventional slow wave, other additional types of wave in the passive cochlea do not appear to play a dominant role in normal passive cochlear function.

PDF
PhD_Thesis_NI_Dec2012.pdf - Other
Download (7MB)

More information

Published date: November 2012
Organisations: University of Southampton, Inst. Sound & Vibration Research

Identifiers

Local EPrints ID: 348820
URI: http://eprints.soton.ac.uk/id/eprint/348820
PURE UUID: 0bc8b94f-f904-4bb5-8278-59e9571722d9

Catalogue record

Date deposited: 04 Mar 2013 14:42
Last modified: 18 Jul 2017 04:47

Export record

Contributors

Author: Guangjian Ni
Thesis advisor: Stephen Elliott

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×