Scalp distribution of early (0 to 10 msec) auditory evoked responses.

Auditory nerve and brain stem evoked responses were summated from multiple scalp and earlobe electrodes from five subjects with normal hearing to determine the spatial voltage relationships along the coronal and/or sagital planes that make up the electrode array. All recordings maintained their positive polarity, and polarity inversions were not observed at any cephalic sites; thus, a null potential line was not identified for these short-latency potentials at the scalp. Less distinct potentials were derived from the earlobes when referenced to the chin. Linked earlobes generated some potentials of negative polarity. These observations lend additional support to the concept that early auditory scalp potentials are most likely generated from far field neural aggregates located caudally to the auditory cortex.