2007 Volume 50 Issue 2 Pages 136-143
We investigated 16 infants who had been referred between 2004 and 2006 to KKR Otemae Hospital for advanced hearing evaluation after newborn hearing screening. The average age of the infants at their first visit was 1.5 months. The first auditory brainstem response (ABR) test revealed normal hearing in 5 of the 16 infants. Since most of the cases had been screened using otoacoustic emission tests, the narrowness of the external ear canal or effusion in the tympanum might have been responsible for the false-positive results. Repeat ABR examination within 6 months showed improvement of the hearing threshold to the normal range in 6 of the remaining 11 cases. This improvement may be explained by the maturation of myelin in the auditory tract.
Although newborn hearing screening results in the referral of a considerable number of infants who eventually show normal hearing, this system remains useful to identify children with hearing impairment before the age of 6 months, which is critically important for determining the need for hearing aids and special education. Since a substantial amount of time is required to evaluate infants, we suggest that more hospitals participate in advanced hearing examination for the early diagnosis of hearing impairment in new-born infants.
