Characteristics of transient-evoked otoacoustic emissions (TEOES) in neonates

Abstract

Transient-evoked otoacoustic emissions (TEOEs) were measured in 1164 ears from 582 neonates without any risk of hearing impairment in order to define basic characteristics useful in deciding if TEOEs could be considered as "normal" in a screening test. Five neonates had no recordable TEOE and ABR thresholds greater than 30 dBnHL. Technical conditions have been analysed using the intensity of the click stimulation, the time necessary to record TEOEs, and the noise floor in the external ear canal (i.e. A-B magnitude). The TEOE magnitude varied between 6.6 dB SPL and 38 dB SPL (mean = 21.75 dB SPL). Only 5% of the tested neonates had a TEOE magnitude lower than 7.75 dB SPL. The TEOE magnitude for the right ear of a neonate was statistically different from those recorded in the left ear (22.4 dB SPL versus 21 dB SPL). The mean TEOE magnitude for male ears was statistically different from those recorded in female ears (21.4 dB SPL versus 22.1 dB SPL).