Electrocochleography with bone-conducted stimulation. A comparative study of different methods of stimulation

Due to the shortcomings of the conventional bone vibrators available at the present, electrocochleography with bone conducted acoustic stimulation has not found any clinical application despite the fact that methods for the procedure have been developed for some time. The most striking deficiencies of these vibrators are their unsatisfactory stimulus intensities and their lack of frequency specificity due to distortion. Driven by an a.c. signal, a piezoceramic accelerometer (A21T, D. J. Birchall Ltd.) was found to meet the requirements of clinical use giving satisfactory stimulus intensities with a minimum of distortion when attached to the mastoid process by means of a modified bone screw.