On the Microphonic Effects in the Labyrinth of the Pigeon and the Function of the Round Window

Abstract

Seldom has a finding in the field of the physiology of the ear been more sensational than the discovery of Wever and Bray in 1930. I quite well remember the deep impression made by the first demonstration of the experiment in the Netherlands, by Rademaker. Differences in potential may also be found in this manner. In the beginning these were regarded as action currents of the acoustic nerve. Davis and Saul (1932) proved that the electric manifestations are twofold: they comprise the action potentials of the acoustic nerve, found by Buytendijk as early as 1910, and an effect named “the microphonic effect of the cochlea”. The cochlea works like a microphone, i.e., the mechanical energy presented to the ear is immediately converted into electrical energy. This holds true for the whole series of audible frequencies. It is generally assumed that the cause must be sought for in a piezo-electric effect. There are various ideas on the localization of this effect.