LINEAR AND NONLINEAR MODEL OF THE HUMAN MIDDLE-EAR

The measurement of the middle ear transfer function usually requires i nvasive methods. An equivalent analog equivalent model enables us to e valuate its characteristics without damaging any part of the ear. A li near and a nonlinear model of the middle ear have been developed to pr edict intracochlear pressure and the stapes volume velocity for variou s sound pressure levels (SPL). The linear model results have been comp ared with human eardrum impedance and middle ear transfer function dat a. The nonlinear phenomena due to the contraction of the stapedius mus cle over 80 dB and to the stapes clipping displacement above 120 dB ar e represented by a set of variable electrical components. The model of the acoustic reflex is based on experimental observations. The study of the annular ligament behavior was performed on cats and extrapolate d to humans with some hypothetical restrictions. These approximations provide information on the middle ear transfer function and enable us to better understand the nonlinear middle ear mechanisms in an intense acoustic field. (C) 1998 Acoustical Society of America. [S0001-4966(9 8)03309-8]