ACOUSTIC IMPEDANCE MEASUREMENTS IN AUDIOLOGY

Abstract

ROYAL IN FIRMARYAcoustic impedance measurements have made important contributions to audiology in physiology. in diagnostic audiology and in the development of earphones for hearing aids and audiometcrs.meioloaThe middle ear provides a coupling between the relatively low impedance at the eardrum and the high impedance of the inner car at the oval window.The impedance of the inner ear is resistive.derived from the interaction of the mass of the cochlear fluid (peril-mph) and the elasticity of the cochlear partition.The ratio of pressure to particle velocity in the cochlea at a point close to .thefootlate of the stapes is approximately 1.12 x 105 l l':I cf water.go = 1.5 x 1 Nsm : ).This is about 300 times greater than the characteris ic impedance of the air in the meatusa disparity which is resolved by the action of the middle ear.