Aim: To characterize age-related changes in brainstem auditory evoked response (BAER) at different click rates from neonates to adults.
Methods: BAER was studied at repetition rates 11-91/sec of clicks in 165 normal neonates and children of various ages and 29 young adults.
Results: BAER wave latencies and inter-peak intervals increased linearly with increasing click rate at all ages. The younger was the age, the greater were BAER click rate-dependent changes. At 9 months and younger, the slopes of latency- and interval-rate functions were all significantly greater than in the adults (all p < 0.01). The slopes of wave I latency- and I-III interval-rate functions at 1-2 years and older were similar to those in adults. The slopes of wave III and V latency-rate functions and I-V and III-V interval-rate function at 3-4 years and older did not differ significantly from those in adults.
Conclusion: BAER is affected by stimulus rate more in younger children than in the older. Adult-like rate-dependent changes are reached at 1-2 years for wave I latency and I-III interval, and 3-4 years for wave III and V latencies and I-V and III-V intervals. Our BAER data at different click rates provide normal references for subjects of various ages.