Difficulties experienced in implementing the ABR travelling wave velocity (Delta V) technique with two commercially available systems.

The ABR Delta V technique involves measuring the difference in latency of the wave V click-evoked ABR in the presence of ipsilateral high-pass noise filtered at 1.42 kHz and at 5.68 kHz. It has been reported that a small latency difference between the two conditions is suggestive of Ménière's disease. The aim of this study was to establish normative data for two commercially available systems. The latency differences obtained in the present study are considerably smaller than those previously reported in the literature. Other problems, including difficulty in identifying wave V in the masked conditions, prevent us from currently using this test technique. There are a number of technical problems which may account for some of the problems experienced when implementing the Delta V technique with commercial equipment and there is at least the possibility that the problems may be overcome in the future.