The Role of the Organ of Corti in Auditory Nerve Stimulation

Abstract

An analysis of the contribution to hearing made by the presence of a normal organ of Corti as compared to direct electric stimulation of the nerve leads to the following conclusions: The portion of the basal turn of the cochlea which can be stimulated contains activity regions primarily limited to frequencies above 5000 Hz. Electrical stimulation of sensory afferent nerve fibers gives rise to sensations of very limited dynamic range compared to normal adequate stimulation through the organ of Corti. Following destruction of the organ of Corti, the speed of nerve degeneration in man is not known, but appears to be slow. Some ganglion cells almost always persist but it is doubtful that these are excitable. The severe nerve degeneration known to be present in most cases of human deafness raises critical questions about the feasibility and logic of a direct stimulation of the auditory nerve in these patients. The unavoidable damage to the capillaries and endosteum of the walls of the scala tympani by insertion of a wire is certain to produce further degeneration and new bone formation.