Numerical analysis of three-dimensional middle ear and inner ear based on nonlinear and viscoelastic constitutive relations.

Hearing is a critical sensory function for humans, and the dynamic behavior of the human ear is influenced by its constitutive relation. In this paper, a finite element model (FEM) of the middle ear with a nonlinear constitutive relation and the inner ear with a viscoelastic constitutive relation was developed based on CT scanning data of the clinical human ear. The frequency-response at the tympanic membrane (TM) and stapes footplate (SF), as well as the amplitude-frequency response and time-domain response curves at different positions of the basilar membrane (BM) were obtained by using the acoustic-solid and fluid-solid coupling dynamic analysis. The results indicated that the previous linear elastic model exhibits an error of 28% relative to experimental data, while the nonlinear-viscoelastic model proposed in this paper demonstrates an error of only 5% relative to experimental data. This model not only better align with the actual biomaterial properties of ear tissue, but also more accurately simulates the mechanical behavior of the human ear during sound perception. The realistic biomaterial model provides a reasonable and accurate numerical simulation platform for studying the biomechanical behavior of the real human ear, laying an applied foundation for related research into hearing damage.