Abstract
Auditory brain-stem response (ABR) and auditory steady-state response (ASSR) were examined in 60 of 450 infants in the neonatal intensive care unit (NICU) of our university hospital. The relationships between the results of evaluation of the ABR/ASSR and the risk factors for hearing loss (gestational age, birth weight, APGAR score, hyperbilirubinemia, severe respiratory disorder, chromosomal abnormalities, and cranial malformation) were evaluated. The thresholds of ASSR and wave V of ABR were well-correlated. Forty-two cases were diagnosed as having normal hearing in the first examination and 18 cases required a second examination. Finally, 11 (2.4% of infants in NICU) cases were diagnosed as showing hearing impairment, including four cases of otitis media with effusion, one case of unilateral hearing loss, and six cases of bilateral moderate to severe hearing loss. Five of the six infants with bilateral hearing loss had three or more risk factors. The second examination revealed that seven of the 18 cases had normal hearing level. Six of the seven cases underwent the first examination less than one month of the revised age. In conclusion, although the percentage of cases with hearing impairment among infants in the NICU is high, the first auditory examination should be performed at more than one month of the revised age.
