RECORDING TECHNIQUES FOR TRANSTYMPANIC ELECTROCOCHLEOGRAPHY IN CLINICAL-PRACTICE

Enhancement of the signal-to-noise ratio is a central issue in electri cally evoked response techniques. Transtympanic electrocochleography r equires careful methodological considerations as responses from the co chlea may easily be affected by various sources of electromagnetic noi se. The final electrophysiological waveforms are acquired by advanced signal processing which influences the content of the recordings. A st andard method of transtympanic electrocohleography is presented here t o increase the feasibility of the measurements in daily clinical use a nd to facilitate uniform interpretation of the recordings. The electro cochleographic recordings were carried out in 61 patients with a clini cal diagnosis of Meniere's disease and in 15 ears of normal hearing su bjects. The electrophysiological data are presented and set in relatio n to the results reported by other laboratories under equivalent recor ding conditions. Methodological factors of consequence for the quality of the recordings, such as testing environment, properties of the equ ipment, mode to produce and deliver stimuli and properties of the elec trodes, are analysed.