A two-dimensional model for the cochlea - II. The heuristic approach and numerical results

An alternative is given for the approach of the two-dimensional problem presented in [12]. Because of the mathematical simplicity of this alternative, several extensions of the model are possible. In this work the compressibility of the perilymph and variations of the scalaheight are considered; other extensions are briefly discussed. The numerical calculations lead to the following conclusions: (1) the results of the one- and two-dimensional models show large quantitative but hardly any qualitative differences; (2) Von Békésy's [1] conclusions concerning the influence of the scalaheight upon the motion of the partition are incorrect; (3) the quantitative discrepancies between the model's results and the experiments of Rhode [6] can be eliminated by a large reduction of the scalaheight; (4) the phase difference as a function of frequency and the phase velocity show no qualitative disparities with the experimental data; (5) models with few sections, such as the hybrid computer model of Hubbard and Geisler [4] are inaccurate.