Middle component averaged electroencephalic responses to tonal stimuli from normal neonates. Initial report.

Tone-pips, centered at 1,000 Hz, were used to elicit middle component averaged electroencephalic responses (AERs) (8 to 90 ms) from five normal neonates. The stimuli were presented monaurally at 10-, 30-, and 50-dB HL, with regard to adult behavioral thresholds. Averaged electroencephalic responses were also derived for no-stimulus control conditions. The initial portion of the stimulus-elicited AER waveforms was similar to that obtained from adults. An objective, scoring procedure, based on predetermined rules, was used to determine peak latencies and to quantify point-to-point amplitudes. Inspection of the scored data revealed that latencies decreased and amplitudes increased as the stimulus magnitude increased, as has also been reported for adults. Unlike adult responses, the middle components from the neonates in this study were identifiable only when recorded from the side of the head ipsilateral to the ear stimulated.