Electrically evoked auditory brainstem response in cochlear implant users.

The waveforms and parameters of electrically evoked auditory brainstem responses, eeABRs, registered in cochlear implant users, were compared with those of acoustically evoked auditory brainstem responses, aeABRs, recorded in normally hearing subjects. The eeABRs, in contrast to the aeABRs, contained dubious Wave IV, while missed Waves VI and VII. The eeABRs possessed also shorter peak-latencies, shorter inter-peak intervals, and greater amplitudes. The revealed differences have been explained by the lack of cochlear mechanisms in cochlear implant recipients. On the other hand, eeABRs and aeABRs exhibited similar stimulus intensity dependence. Both had also lower thresholds, shorter peak-latencies, and greater amplitudes in females than in males.