Transversally inhomogeneous sharply tuned linear cochlear model

Abstract

A linear mechanism of sharp frequency selectivity in the inner ear is developed. The cochlea is assumed to be a slightly varying wave guide with inhomogeneous cross section. The tectorial membrane is considered as an additional mass loading the narrow strip of the basilar membrane that underlies the rows of outer hair cells. A high concentration of mass along the middle line of the cochlea partition provides the sharpening of the tuning curve without significantly altering the phase. The dissipation of energy is assumed to hold in fluid boundary layers near the cochlea partition. The responses of the model with one and the same set of input parameters are compared with different experimental data obtained during the last decade, in the basal and apical parts of the cochlea. This paper demonstrates that a system such as cochlea is capable of performing sharply tuned linear frequency analysis without adding any outside energy to the input waveform to be analyzed.