55 controls were studied to investigate the morphology of brain stem evoked potential, utilizing variable electrode arrays. In a first series the active electrodes placed at Cz and subocciput (SO) were referred to the linked earlobes. In a further 15 recording sessions, Cz, SO and A1A2 were connected to a noncephalic (hand) electrode. In the former array there was a reversed and depressed Vth wave in 95% of the cases at SO, while in the latter the peaks were phase and time-locked at all the recording sites coupled to a depressed IV-V complex from SO and A1A2 in respect to Cz.