Electrode Configuration for Auditory Brainstem Response Audiometry

¹ Electrophysiology Laboratory, House Ear Institute, Los Angeles

A vertical recording montage (C_z to the seventh cervical vertebra or C₇) has been shown to yield significantly lower auditory brainstem response (ABR) threshold when compared with a horizontal or anterior-posterior montage (Sininger & Don, 1989). The present study further examines the relationship between electrode placement and the amplitude of the ABR to low-level stimuli. Four electrode arrays were compared—the commonly-used clinical configuration of forehead to ipsilateral mastoid, the vertical array from the previous study (C_z to C₇), and two additional montages employing linked mastoids as reference to either the vertex or forehead electrode. ABRs were recorded simultaneously in four channels in response to 8000 click stimuli at 10, 20, and 30 dB SL from 9 male and 9 female adult subjects with normal hearing. The effect of electrode channel was significant at <.0001, with the vertical channel revealing the largest wave V amplitudes at all stimulus levels. Female subjects, as expected, produced larger ABR amplitudes than male subjects in all recording conditions, but electrode-channel effects were independent of gender.

Key Words: ABR, electrode, montage

Submitted on July 30, 1991
Accepted on December 13, 1991