Introduction

INTRODUCTION

In the human auditory system, cochlea is one of the most important components. Both mechanical and electrical processing occur in the cochlea. The sound energy present at the eardrum is coupled into a mechanical traveling-wave structure, the basilar membrane, which converts time-domain signal into spatial signal, the frequency depending on the place of x on the basilar membrane. The inner hair cells act as electromechanical transducer, converting basilar membrane vibration into a graded electrical signal. The outer hair cells act as reducing the damping of the passive basilar membrane and allowing weaker signals to be heard.
The silicon cochlea models try to simulate the biological cochlea in separating incoming signal into spatial signal. The silicon basilar membrane is a transmission line with a velocity of propagation that can be tuned electrically. The output taps are located at intervals along the line. We can think about the taps as crude inner hair cells.
In this project, 50 second-order sections with differentiator in cascade build the silicon cochlea models. By using MATLAB program to model the silicon cochlea, we can plot out the basic frequency response of the building block function and silicon basilar membrane function and the frequency response of taps by using the mixed sinusoid signal and the real world sounds as input signal. We have some significant results.
Silicon cochlea models allow us to sharpen our understanding of nature's solution to the hearing problem. It also is an effective solution to a difficult engineering problem.

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