Recent measurements obtained with a variety of techniques have extended von Békésy's observations of cochlear partition mechanics including the traveling wave pattern and the frequency‐place relation. While the cochlear mechanical filter has been shown to be sharper than expected, on the basis of Békésy's results, it apparently is not sharp enough to account for the frequency selectivity observed in auditory nerve fibers. The principal disagreement in the area is whether the vibration of the basilar membrane is linear or nonlinear. Steady‐state nonlinearities that disappear rapidly upon death, transient nonlinear response and two‐tone suppression have been observed in only one species in the mid‐frequency range. Whether this is due to a species difference or a frequency‐place difference remains unresolved.