Electrical stimulation of the ear: experimental studies

The possibility of stimulating the ear by way of an electrode on the round window in order to relieve tinnitus or to produce auditory sensations has been investigated experimentally in guinea pigs. The deleterious effects of DC currents applied to a normal cochlea clearly demonstrate that this means is unsuitable for use in relieving tinnitus in hearing patients. Although AC currents do not cause further damage in ears with the organ of Corti already destroyed by aminoglycosides, the effects of DC currents in such cases have still to be investigated before they can be recommended for the relief of tinnitus in totally deaf patients. Electrical stimulation of the round window combined with masking has made it possible to record responses of auditory neural elements from the eighth nerve to the auditory cortex. This technique could be promising for the basic study of the central auditory nervous system, both experimentally and clinically, and could lead to a more accurate evaluation of candidates for cochlear prostheses.