The equality of volume displacements in the inner ear windows.

The equality of volume displacements in the inner ear windows is commonly assumed. In the present work this assumption is experimentally verified. The stapes is given a known displacement. The volume displacement of the round window is determined by measuring the sound pressure set up in a tube cemented to the round window. Inner ears of pigs have been used in the investigation. Supplementary measurements on one human temporal bone have been performed. The equality of the volume flows in the inner ear windows is also supported through an analysis of earlier measurements of the round window displacement for a given sound-pressure level at the eardrum.