Clinical significance of SP/AP ratio in inner ear diseases.

Electrocochleogram was recorded from 28 ears affected by Ménière's disease , 27 ears affected by sensorineural hearing loss resulting from hair cell damage and 22 normal ears as controls in response to tone bursts in order to evaluate diagnostic significance of the summating potential/action potential (SP/AP) ratio and the SP amplitude. The fundamental aspects of the SP/AP ratio were studied in relation to frequency, intensity and rate of tone burst stimuli. It was concluded from present results that the SP/AP ratio can be a useful indicator to detect -SP dominance, while the SP amplitude can be an indicator to detect cell damage in inner ear diseases.