Transient evoked otoacoustic emissions in newborn infants: Effects of ear asymmetry, gender, and age.

Our aim was to examine the effects of gender, ear asymmetry, and age of infants on various parameters of transient evoked otoacoustic emissions (TEOAEs). Three hundred thirty-two infants (181 males, 151 females) were tested using the ILO292 Otodynamics Analyzer (Otodynamics Ltd, England) as a screening procedure. The subjects were divided into two age groups: group 1, newborn infants prior to hospital discharge (mean age of 4 days), and group 2, infants at the 1-month-old health checkup (mean age of 35 days). Responses to TEOAE stimuli were recorded at 1.0, 1.5, 2.0, 3.0, and 4.0 kHz. There were significant effects of gender and ear (left/right) on the signal-to-noise ratio, response level, and whole-wave and band reproducibility values in TEOAEs. The right ear had higher values of whole-wave reproducibility, response level, signal-to-noise ratio, and band reproducibility than the left ear. Females displayed higher whole-wave reproducibility, response level, band reproducibility, and signal-to-noise ratio values than males. There was no significant difference in response level, signal-to-noise ratio, and band reproducibility between the two age groups. The findings of the present investigation may contribute toward future improvements in neonatal hearing screening based on the community.