Click evoked otoacoustic emissions: inter-aural and gender differences in newborns

Click evoked otoacoustic emissions (CEOAEs) are an objective and reliable method of assessing cochlear status, particularly suitable for newborns. This study aimed to assess CEOAE inter-aural and gender differences. Other non-auditory factors, such as infant's head size and weight, were considered. Band averaged CEOAEs were analyzed for 120 healthy, full term newborns, 61 females and 59 males. The babies were randomly selected from the nursery and tested in a quiet room away from the ward, using an Otodynamic ILO 92 system. The CEOAEs of the females were significantly larger than those of the males. For the frequency bands 2, 3, and 4 kHz and for the overall response, the emissions were larger in the right ear, for both males and females. These inter-aural differences were more pronounced in male subjects than in female subjects. These findings may reflect the accumulating evidence that differences exist in efferent cochlear inhibition.