The influence of reference electrode position on recordings of the auditory brainstem responses.

The general routine for recording the auditory brainstem responses (ABR) includes the use of earlobe electrodes as reference. Electrically linked electrodes on each side of the neck are almost indifferent with regard to the ABR, and such electrodes were used as reference in an analysis of the response patterns at the vertex and both earlobes. These contribute very significantly to conventional recordings, and it is preferable to use an indifferent electrode as reference for the active vertex electrode. If this measurement is supplemented with a differential recording between the 2 earlobes, the N1 of the whole nerve action potential and other parts of the early ABR are easy to identify and the diagnostic possibilities in pathological cases will be improved.