[The importance of auditory canal electrodes for improving BERA recording]

During BERA examinations using common surface leads (forehead, mastoid process or ear lobe) wave I is not always distinct. Contrary to hitherto used methods (needle electrodes, small electrodes fixed by means of a cross-bar), the authors recommend to make wave I more distinct by use a surface electrode with a larger area (78 sq.mm). It is an open silver tube which, if necessary, is fixed in the osseous portion of the external auditory meatus by a PVC tube. Examination of 50 subjects revealed that the amplitude of wave I increased by using the electrode on an average more than four times, the thresholds of wave I in healthy subjects are practically identical as the thresholds of the V wave. The authors did not observe any effect on the thresholds and latencies of the V wave. The examined subjects tolerated the electrode well.