Analysis of the Latency of Auditory Brainstem Response Wave V in Infants According to Age, Hearing Threshold and Stimulus Intensity

Abstract

Background and Objectives The latency of auditory brainstem response (ABR) wave V shifts depending on age, hearing threshold, and stimulus intensity. This study was performed to examine the latencies of ABR wave V in infants with normal hearing and sensorineural hearing loss.Subjects and Method The retrospective review of ABR of 318 infants (539 ears) was performed. The patients were divided into four groups according to age at the time of the ABR test (group A: 0-2 months, group B: 3-5 months, group C: 6-8 months, and group D: 9-11 months). The test was performed using click sound under sedation, with the stimulus intensity adjusted by 10 dB intervals. The latency of wave V was analyzed according to age, hearing threshold, and stimulus intensity.Results Normal hearing was detected in 320 ears (wave V threshold of 20 dBnHL or less) and sensorineural hearing loss was found in 219 ears. Wave V latencies decreased with increase in age and stimulus intensity in both normal hearing infants and hearing-impaired infants. The ears with higher thresholds showed longer latencies at the same stimulus intensity. The normative data of wave V latency of infants with varying hearing thresholds according to age and stimulus intensity could be determined.Conclusion The present study examined the latencies of ABR wave V of hearing-impaired and normal hearing infants according to age and stimulus intensity. The data will help audiologists to evaluate the hearing of infants who are referred for ABR test.