Network concepts and energy flow in the human middle-ear

Abstract

The primary function of the middle-ear is the transmission of sound energy from the earcanal to the cochlea. It follows that the energy flow through the system and energy loss within it are major considerations in middle-ear modeling. These considerations are paramount at high frequencies where the fraction of energy transmitted is small (roughly 2% for the human ear at 10 kHz) and the role of the eardrum is crucial. A review of the evidence bearing on this role leads to an updating of the acoustical network for the human middle-ear advanced in 1977 (J. Acoust. Soc. Am. Suppl. 1 62, S12) and a more refined estimate of the middle-ear transmission curve. This work takes into account recent measurements of earcanal pressure ratio, values of eardrum velocity ratio for the compound eardrum derived from holographic data, and a revised estimate of eardrum dimensions.