Auditory evoked potentials in premature and full-term infants

Abstract

Accurate information about type, degree, and configuration of hearing loss are necessary for successful audiological early interventions. Auditory brainstem response with tone burst stimuli (TB ABR) and auditory steady-state response (ASSR) exams provide this information. Aim: To analyze the clinical applicability of TB ABR and ASSR at 2 kHz in infants, comparing responses in full-term and premature neonates. Material and Method: The study was cross-sectional, clinical and experimental. Subjects consisted of 17 premature infants and 19 full-term infants. TB ABR and ASSR exams at 2000 Hz were done during natural sleep. Results: The electrophysiological minimum response obtained with TB ABR was 32.4 dBnHL (52.4 dBSPL); the ASSR minimum was 13.8 dBHL (26.4 dBSPL). The exams required 21.1 min and 22 min, respectively. Premature and full-term infant responses showed no statistically significant differences, except for auditory steady-state response duration. Conclusions: Both exams have clinical applicability at 2 kHz in infants, with 20 min of duration, on average. In general, there are no differences between premature and full-term individuals.