A computational model for cochlear mechanics

Abstract

An integral equation model of the cochlea [M. D. Lien and J. R. Cox, Jr., J. Acoust. Soc. Am. 55, 432(A) 1974), J. B. Allen, J. Acoust. Soc. Am. 61, 110–119 (1977)] was revised by separating fluid mechanics and partition dynamics to allow computation of the response to complex stimuli and inclusion of nonlinear partition characteristics. The formulation is based on identifiable cochlear features: channel morphometrics and partition mass, resistance, and stiffness. Several simplifications not fundamental to the approach were used: Channel cross sections were assumed equal and independent of longitudinal position; dependence on the transverse coordinate was neglected; perilymph was assumed inviscid and incompressible; channel walls were assumed rigid except for the cochlear partition and windows. A spatial representation bandlimited by the number of computational elements was used, but otherwise no assumptions were made regarding the wavelength of the partition or fluid motion. The implementation of the model computes for an arbitrary input the instantaneous distribution of partition motion or the moving-window, discrete Fourier transform of partition amplitude and phase. [Work supported by NIH RR00396.]