Influence of the Operations of the Middle and Inner Ear on Evoked Otoacoustic Emissions in Guinea Pigs

Abstract

Influence of the operations of the middle and inner ear was examined after recording transiently evoked otoacoustic emissions (TEOAEs) to a click stimulus in guinea pigs by using the ILO88. After opening of auditory bulla, TEOAE power under 2kHz in FFT pictures (FEP-2) was increased significantly. On the other hand, TEOAE power between 2 and 4kHz in FFT pictures (FEP2-4) did not change after the operation. The filling of physiological saline in the bulla developed disappearance of TEOAE powers reversibly.
Total echo power was decreased slowly after destruction of the cochlear apical turn. To be precise, FEP-2 was decreased more quickly, and then FEP2-4 decreased. TEOAE power above 4kHz was decreased finally. These results implied that click evoked otoacoustic emission is frequency specific to some extent.