The cochlea, the part of the inner ear responsible for hearing, consists of a fluid-filled tube and two membranes. This Demonstration models the cochlea by a partial differential equation (specifically, a spatially varying wave equation). The plot shows the spatiotemporal pattern generated when the left boundary is driven sinusoidally at various frequencies. The cochlea performs a frequency-to-space transformation: as the input frequency increases, the position at which the wave cuts off moves to the left. You can change the input frequency, transmission loss, impedance, spatial scaling constant (" scale"), the time for which simulation will be carried out, and the number of points to plot in space and time (" points" and " points", respectively).