Bone Conduction Hearing: Three-Dimensional Finite Element Model of the Human Middle and Inner Ear

A finite-element (FE) simulation model of a human auditory periphery was developed to gain insight into the fundamental mechanisms of bone conduction (BC) hearing. Three dimensional geometry of middle ear and cochlea including semi-circular canal was obtained by mu CT images. The simulation effectively focused on the middle ear and then the cochlea fluid-inertial BC component. The FE model was first tuned and validated against various frequency responses available from the literature. The characteristics of various cochlear response quantities such as the basilar membrane (BM) displacement, window volume velocities, and cochlear fluid pressure were examined for both BC and air conduction (AC) excitations. Especially, the decomposition analysis was applied to window volume velocities and cochlear fluid pressures to separate them into anti-symmetric and symmetric components. The preliminary result shows that the BM vibration is driven by the part of the fluid pressure that is anti-symmetric (i.e. differential slow wave) with respect to the BM, which is generated by the anti-symmetric window volume velocity.