The mechanism of the middle ear: I. The two piston problem

The drum, ossicles and oval window of the middle ear can be considered equivalent to a system of two pistons connected by a lever, where the leverage results not only from the combined motion of the three ossicles, but also from the non-rigid fibrated structure of the drum. This paper studies the transmission of sound from air to liquid by means of such a system and finds conditions on the dimensions, mass and elasticity of the system which should be met in a “good” ear. Two methods, based on different conceptions of “good,” are used, and they give similar results. Most of these results are in good quantitative agreement with actual data.