Fluid dynamical, micro-structural and electrical responses of the cochlea: Active case.

<p>The three columns represent the responses at the base, middle and apex respectively. When the stapes is vibrated at 18.6, 4.4 and 0.78 kHz, the responses peak at x = 2, 6 and 10 mm, respectively. The stapes velocity amplitude is 1 nm/ms. (<b>A</b>) Cochlear fluid pressure amplitude referenced to the pressure at the round window. The unit for the pressure scale is mPa. (<b>B</b>) Spatial pattern of the BM (basilar membrane) and the TM (tectorial membrane) vibration at the same moment of time. (<b>C</b>) Vibration patterns of the 3-D finite element model of the OCC. A 1-mm section around the peak (thick bars above the x-axes in (B)) is shown. The color contours of the top (TM) and the bottom (BM) structures indicate transverse displacement amplitude at a moment of time. Red and blue colors represent the displacement toward the scala vestibule and toward the scala tympani, respectively. (<b>D</b>) Normalized amplitudes of membrane potential (green) and mechano-transduction current (red) of the outer hair cells plotted together with the BM displacement (black). The numbers correspond to the peak amplitudes of receptor potential (in mV), transduction current (in nA) and BM displacement (in nm).