Volume-pressure properties of round and oval windows. A quantitative study on human temporal bone.

A model study was carried out on human temporal bones to assess quantitatively the displacement of the round and oval windows when different pressure levels were applied to the external ear canal and inside the middle ear. It was found that the major displacements of the window membranes occurred in the pressure range of +/- 20 cm H2O in the intact middle ear. An additional increase in the middle ear pressure up to +/- 70 cm H2O caused a minor displacement of the window membranes.