Single Tone Propagation


This simulation shows how a pressure wave in the cochlea travels at first with a rather low amplitude and a high velocity. As the wave travels it slows down as its velocity decreases and thus its amplitude grows. Eventually the wave is travelling so slowly that it dies down due to membrane losses.

This Mathematica animation shows the pressure wave at the membrane of a pure tone as it propagates down the cochlea. Where it first enters the cochlea, on the left, it has a high propagation speed. As the wave travels, it slows down and the energy starts to bunch up. Beyond a point of maximum response the pressure wave quickly dissipates. The losses in the cochlea are still relatively small here, but the wave is traveling so slowly that it is strongly attenuated before it travels much farther down the cochlea. This very slowly traveling wave accounts for the steep attenuation measured by hearing researchers. A rather broad 'pseudoresonance' describes the resulting response.

Time Delay