This animation is an attempt at a simple illustration of a cochlear travelling wave. It is not a physiological model and is simply meant as a tool for teaching/learning. Things to note: (1) Changing the frequency changes the distance from the stapes at which the peak of movement occurs; (2) The envelope of the excitation (movement) is asymmetrical; (3) the travelling wave appears to slow down and the wavelength shorten near the peak of excitation (this element needs further work).
Changees in amplitude of movement or envelope spread towards the base with signal level are incorporated for illustrative purposes, but are not attempts to model real cochlear behaviour.