Evaluation of auditory brainstem responses for hearing screening of high-risk infants

Auditory brainstem responses (ABR) were recorded in 30 normal and 60 high-risk neonates with gestational age between 30 and 45 weeks. The normative data of normal group as regard to age, sex and various parameters of ABR were compared with high-risk group. ABR parameters especially wave V and interwave V-I intervals were significantly prolonged in high-risk infants. An infant was considered to "pass" the ABR test if an identifiable and replicable wave V response was present at 30 dB HL in both ears. All the normal neonates had click thresholds consistent with normal hearing. 12 of the highrisk neonates showed mild to moderate hearing impairment (absent replicable wave V at 30-60 dB HL) and 2 of them showed severe to profound hearing impairment (absent replicable wave V at 70 dB HL). 9 of the "failed" group were reevaluated within 3 months and several times thereafter if the abnormal responses persisted. 2 (3.3%) infants showed persistent hearing loss, which was confirmed later by behavioral audiometry.