Acoustics-Structure Coupled Analysis And Its Application In Simulation Of Sound Transmission In Ear

The coupled analysis with finite element method is a way of simulating sound transmission in human ear. The influence in sound transmission by changes of middle ear structure was simulated through calculating the acoustics-structure model.In this thesis, a coupled model was established, including air in ear canal and middle ear cavity, middle ear, fluid in the simplified straight cochlea. Through the coupled calculation, some results were derived, such as displacement of stapes footplate and tympanic membrane, press gain in middle ear, pressure distribution in cochlear etc. And a simplified cochlear model was built with reference to some achievement of researchers; the frequency sensitivity of the basilar membrane motion was predicted along the length of the basilar membrane from the basal turn to the apex.Based on the analysis above, with the established cochlear model, the process of reverse sound transmission was simulated from cochlear to middle ear by round window stimulation, and pressure distribution in scala vestibuli, differential pressure between scala vestibuli and scala tympani were derived by calculation.At last, the integrated finite element model of middle ear and implantable middle ear hearing aids was built. Using this model, displacement responses of tympanic membrane and stapes footplate were derived before and after implanting the hearing aids, and the mass loading influence of the transducer on transmission function of middle ear was analyzed in different attachment conditions.Results of displacement response of tympanic membrane and stapes, pressure gain of middle ear and round window,differential pressure distribution in reverse sound transmission etc. were consistent with the related experimental results in the published literatures, which convinced rationality of middle ear model, simplified cochlear model and its mechanical property. So,the integrated model of middle ear and simplified cochlea could apply in numerical simulation of middle ear and basilar membrane motion further under different conditions.