Extra-tympanic electrocochleography.

A non-invasive technique for recording the cochlear action potential in adults without recourse to sedation or local anaesthesia is presented. This technique has been assessed in two ways: (1) A group of normal subjects was tested to obtain distributions of response amplitude and latency as functions of stimulus intensity. (2) A group of patients with Meniere's disease was tested with trans- and extra-tympanic electrocochleography to compare the intensity amplitude functions and wave-forms obtained from the two methods. On the basis of this study the use of extra-tympanic electrocochleography as a replacement for the trans-tympanic method is discussed.