Especially prominent cochlear microphonic activity in the auditory brainstem response.

Recent recommendations to record cochlear microphonic (CM) activity in auditory brainstem response (ABR) waveforms are being driven by reports of 'especially prominent' (Starr et al, 2001, p. 92) CM activity in ABR waveforms that were absent or grossly abnormal. This paper adds to these recommendations by providing the first description of especially prominent CM activity in ABR waveforms that were present and not grossly abnormal. The implications of this description are discussed via a review of the possible non-pathophysiological and pathophysiological causes of especially prominent CM activity in auditory evoked potentials.