Some Considerations of Multichannel Electrical Stimulation of the Auditory Nerve in the Profoundly Deaf; Interfacing Electrode Arrays with the Auditory Nerve Array

Abstract

The problems inherent in development of multichannel electrical stimulation prosthetic devices with potential application to profoundly deaf subjects have been summarized, collectively, by a number of scientists who have considered overall developmental strategy in the framework of basic cochlear anatomy and pathology, cochlear physiology and the speech sciences; within the framework of clinical application; and within the framework of feasible engineering (e.g., see Simmons, 1969; Kiang, 1975; Kiang & Moxon, 1972; Merzenich, 1975; Schindler et al., 1977; Black, 1978). Obvious requirements for such devices include: (a) Electrodes must excite the auditory nerve in an appropriate way. (Only some of the characteristics of what constitutes an “appropriate way” have been resolved.) (b) Implanted devices and surgical implantation procedures must be acceptably safe; they must not lead to significant further destruction of the auditory nerve array, (c) Electrical stimulation at required current levels must be safe, and nondestructive re the auditory nerve array, (d) Appropriate “optimal” coding of sound must be defined for both speech processing and nerve stimulation stages of implanted devices. (e) Implantable electrodes and electrode driving hardware and external sound processing devices delivering “optimally coded” information must be fabricated. Surival characteristics of implantable devices must guarantee lifelong operation of the multielectrode array and acceptably long survival (and a convenient replacement strategy) for implanted telemetry hardware.