Progress Toward a Successor to the Cochlear Implant

The efficacy of a neural prosthesis ultimately is limited by the quality of the electrode/neural interface. Present-day cochlear implants lie in a separate anatomical compartment from the target neural tissue, behind a bony wall. We are testing the feasibility of an alternative approach, which brings stimulating electrodes in intimate contact with restricted frequency-specific populations of auditory-nerve fibers. We employ a multi-electrode array that penetrates the modiolar trunk of the auditory nerve, crossing the array of fibers from the entire tonotopic spiral. By all measures that are possible in anesthetized animals, this intraneural stimulation out-performs conventional cochlear implants. The seminar will review progress to date and will address the challenges of translating this technology to human patients.