Research paperEffects of a perilymphatic fistula on the passive vibration response of the basilar membrane

In this study, a three-dimensional finite-element model of the passive human cochlea was created. Dynamic behavior of the basilar membrane caused by the vibration of the stapes footplate was analyzed considering a fluid-structure interaction with the cochlear fluid. Next, the effects of a perilymphatic fistula (PLF) on the vibration of the cochlea were examined by making a small hole on the wall of the cochlea model. Even if a PLF existed in the scala vestibuli, a traveling wave was generated on the basilar membrane. When a PLF existed at the basal end of the cochlea, the shape of the traveling wave envelope showed no remarkable change, but the maximum amplitude became smaller at the entire frequency range from 0.5 to 5 kHz and decreased with decreasing frequency. In contrast, when a PLF existed at the second turn of the cochlea, the traveling wave envelope showed a notch at the position of the PLF and the maximum amplitude also became smaller. This model assists in elucidating the mechanisms of hearing loss due to a PLF from the view of dynamics.

► A fistula at the scala vestibule decreases BM amplitude. ► The fistula changes the shape of the traveling wave envelope and may affects speech recognition. ► A round window fistula scarcely changes the vibration of the BM.