posted on 2014-12-15, 10:37authored byDavid Rogers. Sewell
This thesis offers a critical review of past and present techniques in the field of modelling the auditory periphery whilst concurrently describing the evolution of a novel computer based demonstration platform. Modelling techniques used to simulate the progression of sound from the free field to the auditory nerve are reviewed and the advantages afforded by the parametric approach are argued. The underlying philosophy of the modelling framework is to provide a transparent model, in which components are mapped directly to related components in the real system, that is readily extensible in the light of new data, and provides a re-usable platform on which to test theories of audition.;The framework provides models of the major 'stages' in the auditory periphery. The acoustic meatus can be defined using any known cross sectional area variation. The tympanum can be ascribed regional properties and the middle ear model, within the framework, allows investigation into the effects of the air cavities and the acoustic reflex. The geometrical relationships between the physiological structures within the organ of Corti are specifically defined throughout a cochlea model and incorporated to a coupled model of the basilar membrane and scala fluids. The framework provides a platform for investigation of theories of active mechanics and includes models of stereocilia deflection and adaptation, as well as simple compartmental models of ion transfer surrounding the outer hair cells (OHC), and fast motile OHC responses. As simulation takes place in the time domain, investigations into cochlear transduction are not limited to single sinusoidal input, thereby enabling the transduction of speech and time varying cochlea phenomena to be addressed.