Search techniques applied to middle ear models

The response of the middle ear to acoustic signals at the eardrum can be described using a mechanical model [see for instance, Y. Onchi, J. Acoust. Soc. Am. 33, 794–805 (1961)]. The transfer function between the input to the middle ear (pressure at the eardrum) and the output (velocity at the stapes) is obtained for such a model. The appropriate values of masses, spring stiffnesses, and resistance of dampers are still not exactly known. A search technique using the Newton-Raphson method has been used to find the best values of these parameters to fit measured transfer functions [A. R. Moller, J. Acoust. Soc. Am. 35, 1526–1534 (1963)]. Preliminary results for the values of the various parameters using this procedure are compared with previously obtained experimental results. The closeness of the fit of the transfer function is also determined and the effects of modifications of the model are investigated.