[Correlation between auditory threshold and transitory evoked otoacoustic emissions]

Abstract

The aim of this study was to compare transiently evoked otoacoustic emissions (TEOAE) and pure tone audiometry in normal hearing ears and ears with cochlear hearing loss (60 ears of 30 subjects), to obtain defined data on qualitative and quantitative correlations. We wanted to determine the reliability with which a clinical examiner could predict a typical, idealized audiometric configuration from TEOAE measurements. The results show that the presence of otoacoustic emissions drops as a function of hearing loss and that there is a highly statistically significant correlation between characteristics of otoacoustic emission (coefficient of correlation and strength of otoacoustic emissions) and hearing loss at 1000-3000 Hz frequency. Otoacoustic emissions are never found when hearing loss at 1000-3000 Hz exceeds 36 dBnHL. The main practical conclusion is that otoacoustic emission presence indicates middle frequency functional integrity of the outer hair cells of Corti's organ. Absence of otoacoustic emissions is harder to interpret and requires further audiological diagnosis (brain-stem auditory evoked potentials).