The finite element (FE) method was used to analyze the effect of geometric nonlinearity on the sound transmission of human ear at different middle-ear pressures. An FE model of the human ear consisting of the external ear canal, middle ear and simplified cochlea was first constructed. The validation of this model was accomplished by comparing the model-derived results with experimental data. Furthermore, based on the finite deformation theory, the effect of large deformation and prestress on the stiffness matrix of human ear system was taken into consideration. The frequency responses of eardrum umbo and stapes footplate displacements of the frequency ranging from 250 to 8 000 Hz were then calculated as the static pressure varied from -2.0 kPa to +2.0 kPa. The results show that, when only geometric nonlinearity is considered, the positive middle-ear pressure mainly affects the dynamic characteristics of human ear at low frequency from 0 to 2 500 Hz. The structures in middle ear are softened by positive pressure, but negative pressure results in middle-ear structural stiffening. © 2015, Editorial Board of Journal of Shanghai Jiao Tong University. All right reserved.
(8.0+极速模式)