Amplitude effects on electrocochleography outcomes.

Abstract

Electrocochleography measures in humans were examined to determine factors affecting results. Retrospective study. Analysis was performed on data from 479 patients seen from 1998 to 2002 who underwent electrocochleography with a tympanic membrane electrode. Measures from click evoked electrocochleography (the summating potential to action potential ratio [SP/AP]) were compared with tone evoked electrocochleography (the SP amplitude). Findings indicate a strong correlation between click and tone measures if the AP from click measures was over 1 microV (P <.001), but no significant correlation between these measures if the AP was under 1 microV. Results were also analyzed with respect to patient hearing sensitivity and final diagnosis. Tympanic membrane electrocochleography is more efficacious when the AP from click stimulation is over 1 microV.