Further differences between brain-stem auditory potentials evoked by rarefaction and condensation clicks as revealed by vector analysis.

Vectorial analysis of the brain-stem auditory evoked potential (BAEP) elicited by either condensation and rarefaction stimuli was performed in 22 healthy subjects. Besides differences in latency of components III and V ('R' longer than 'C'), a significant difference was found between the directions of the vector calculated over the descending limb of wave III, with an ascending direction for 'C' responses and a contralateral direction for 'R' responses. The possible origins of these differences are discussed. It is concluded that the use of alternating or isolated single polarity clicks is not recommended, mainly when assessing integrity of central auditory pathways.