Brainstem auditory responses (BAER) performed on 667 high risk infants from an infant special care unit were evaluated at the Department of Otolaryngology, University of Texas Medical Branch, Galveston, Texas. Infants who failed the test were classified into two groups; those who failed at 30 dB hearing level and those who failed at 45 dB hearing level. At follow-up examination in one, three, or six months, 8 (1.2%) had severe sensorineural hearing impairments (since only 50% returned for follow-up, 2.4% was a more accurate incidence). Conductive hearing loss was found in 15.7% (17/108) of those who passed 30 dB level and in 34.3% (12/34) of those who failed. The use of BAER testing at levels less than 45 dB permitted detection of middle ear disorders. All of the infants who failed at 45 dB hearing level and had abnormal results at the 3-4 month follow-up examination had severe sensorineural or moderate to severe mixed hearing losses. For the group that failed at 30 dB hearing level and were abnormal at follow-up, 80% had conductive hearing disorders and 20% had mild sensorineural hearing impairments. Infants enrolled in a parent-infant program for hearing impairment by 6 months of age were referred from the BAER program. [1]

COMMENT. The brainstem auditory evoked response test (BAER) is effective in the early detection of hearing impairments in high risk neonates, and the degree and type of hearing loss may be predicted. However, the children who were referred to the BAER program represented only 31% of the total number of parent-infant program children with congenital hearing impairment and only 50% of the children with multiple handicaps. Some of the hearing impaired children entering the parent-infant program at this center during the period of the study were referred from sources other than the BAER program and were much older when enrolled. An infant hearing assessment program for only high risk infants would fail to identify approximately one-half of hearing impaired children.