Auditory brainstem responses and clinical follow-up of high-risk infants.

Auditory brainstem response (ABR) evaluations were performed on 667 high-risk infants from an infant special care unit. Of these infants, 82% passed the ABR. Those infants who failed the ABR were classified into two groups, those who failed at 30 dB hearing level and those who failed at 45 dB hearing level. All of the infants were encouraged to return for otologic/audiologic follow-up in 1, 3, or 6 months, depending on the initial ABR results. All of the infants with severe hearing impairments came from the group who failed at 45 dB hearing level. The incidence of severe sensorineural hearing impairment in this population was estimated to be 2.4%. For the group that failed at 30 dB hearing level, 80% of those who were abnormal at follow-up were considered to have conductive hearing disorders and 20% had mild sensorineural hearing impairments. In addition, infants enrolled in a parent-infant program for hearing impaired by 6 months of age were from the ABR program; however, several infants entered the parent-infant program at a relatively late age because they did not meet the high-risk criteria, they were from other hospitals, or they were not detected by the ABR program.