A theory of cochlear input impedance and middle ear parameter estimation

In this thesis it is hypothesized that the geometry of the cat cochlea has evolved to maximize sound transmission from the eardrum to the cochlea. This hypothesis is shown to be tenable by modeling the cochlear input impedance and the middle-ear. It is also hypothesized that the geometric configuration of the middle-ear cavities plays an important role in its acoustic properties.;Various aspects of the cat cochlear input impedance ;To quantify the effect of ;A physical model for the middle-ear cavities is presented. The model explicitly takes into account effects of non-planar wave propagation due to area discontinuities and visco-thermal effects at the walls. This model is experimentally verified by making impedance measurements on several cylindrical cavities with area discontinuities in its acoustic path.;The models for the ossicular path and middle-ear cavities are combined to obtain a comprehensive model for the "intact" cat eardrum impedance.