Inertial bone conduction: symmetric and anti-symmetric components.

摘要: Of the two pathways through which we hear, air conduction (AC) and bone (BC), fundamental mechanisms of BC pathway remain poorly understood, despite their clinical significance. A finite element model a human middle ear cochlea was developed to gain insight into hearing. The characteristics various cochlear response quantities, including basilar membrane (BM) vibration, oval-window (OW) round-window (RW) volume velocities, fluid pressures were examined for as well AC excitations. These responses tuned validated against available experimental data from literature. excitations simulated in form rigid body vibrations surrounding bony structures x, y, z orthogonal directions. results show that BM vibration are essentially invariant regardless whether excitation is via BC, independent direction, or AC. This at first appeared surprising because differ considerably depending on mode. Analysis reveals responds only lower-magnitude anti-symmetric slow-wave pressure component not symmetric fast-wave component, dominates magnitude total field. produced by window velocities. As result, effectively driven OW RW irrespective type excitation. Middle modifications alter velocities corroborate this assertion. current provide further clarification underlying Bekesy’s “paradoxical motion” concept.