Abstract
Two mechanisms have been proposed for outer hair cells(OHCs) mediated amplification in mammalian cochlea : a hair-bundle(HB) motility generated during mechano-electrial transduction(MET) and a somatic motility generated by motor protein prestin in the outer hair cell lateral membrane. Both mechanisms are nonlinear. In the first section, this thesis uses computer models to simulate the outer hair cell fast effect by efferent control from medial olivocochlea interneuron. The middle-ear to inner ear and outer hair cell model proposed by Liu and Neely in 2009 and 2010 were adopted for this purpose. In the second section, with recent advance in molecular biology, the amount of prestin can be changed in all outer hair cells in the cochlea using novel knock-in techniques. This thesis simulated the effects on hearing curves with altered gene expression. The results of simulation in high frequency region of the cochlea are consistent with literature in that the outer hair cell nonlinear capacitance and somatic motility are not linearly correlated with the gain of the cochlea amplifier. Base on the computer model, insight regarding the cochlea frequency responses at low frequency region is also provided.