Effect of contralateral noise on the middle components of the averaged electroencephalic response

Middle-component AERs were obtained from normal-hearing adults to 1000-Hz tone pips at 20 and 40 dB SL and at silent control. A continuous noise at 20, 40, and 80 dB SL and at silent control was presented to the contralateral ear. When the tone pips were at 20 or 40 dB SL, five peaks were identified visually in waveforms constructed by digitally adding AERs across subject and replication. Peak latencies determined from the composite waveforms for each signal-masker condition were used as time points to measure point-to-point amplitudes in individual AERs. The masker at 20 or 40 dB SL did not alter or degrade the AER produced by the tone pip. It was concluded that clinical masking may be used in EEA when the middle components of the AER are employed as a response index.