Middle component AERs from neonates to low-level tonal stimuli.

Ipsilateral and contralateral middle-component AERs (8-90 ms) were recorded from 20 normal neonates. AERs were elicited with either 500-Hz or 3000-Hz tone-pips presented monotically at 10, 30, and 50 dB HL. AERs also were obtained for silent control conditions. In general, latencies decreased and amplitudes increased with increasing stimulus level. Responses to 500-Hz tone-pips were larger than those for 3000 Hz. The results are similar to those obtained from adults. The neonates' middle-components, however, differ from those of adults in terms of the small contribution of the electroencephalic activity beyond 60 ms, and in the asymmetry between the ipsilateral and contralateral AERs.