Figure 34.16: Frequencies in Sound Pressure Waves Are Transduced into Signals from Distinctive Sets of Hair Cells (A) Each frequency causes oscillations at a particular region of the basilar membrane. Here low-frequency sound pressure waves are shown flexing a region of the basilar membrane far from the oval window. (B) Different regions of the basilar membrane move in response to different frequencies because of the gradations in the membrane’s width and stiffness. Hair cells positioned along the basilar membrane produce signals that lead to generation of action potentials that encode the regions that are oscillating.