ANALYSIS AND MODELLING OF THE INNER EAR

Abstract

This Dissertation deals with the Analysis and Modelling Of The Inner Ear, specifically the human ear. The work can be divided Into two major sections. The first section Is that which deals with the study and analysis of the auditory system, that is the basic anatomy and physiology of the auditory system with much emphasis given to the inner ear. For this purpose, a concise but detail description of the system is given. The second part of the Dissertation work Is on modelling of the Inner ear, for which an over view and the basis for the choice between the common types of the different models followed by investigation of the mathematical model on signal generation within the inner ear based on the previous model Is given. Starting from the basic theoretical background of the inner ear and the available mechanics of the cochlear partition, a new mathematical model Is presented. The model explains the way the inner ear behaves under external (that is, sound) stimulus. It Is found that a polynomial function of the fourth order having different coefficients at different distances from the stapes is a good approximation for the range of frequencies, the human ear is known to respond.. Two major areas, the author believes the model would find applications, are given as a hypothetical case study. One of them is, In diagnostic purpose where an expert system can be developed using experimental values, so that the polynomial function can now be used to determine the condition of the Inner ear. In order to show how this is accomplished a stiff basilar membrane is assumed and a polynomial function with the same degree of polynomial as that of the supposedly normal case Is derived. And then, the deviation from the original and the way the coefficients of the assumed stiff Basilar Membrane varies will indicate the condition of the partition from the stapes. The second area of application is in cochlear implant prosthetic device for hearing impaired people, where the model developed here can be used as the basic algorithm In the processor of the system. Although, both cases are termed hypothetical, the only requirement needed to prove would be to get the experimental data, which I believe will be the immediate scope of this dissertation work.