There is a rapidly growing need for cochlear implants to address hearing disability transforming the lives of the young congenitally hearing disabled, as well as people in their productive working lives, and senior adults. With an aging population, the number of people with profound hearing loss which cannot be addressed by conventional acoustic hearing aid devices is expanding rapidly.  Cochlear Ltd, as a leading manufacturer of hearing prosthetics, has recently passed a milestone of more than 500,000 cochlear implant systems delivered to meet these needs.

Cochlear implants have transformed the prognostic landscape for many, enabling excellent speech perception. However, for other cochlear implant recipients, the performance of the device has been of moderate to minimal benefit. This largely reflects the variation in the pathophysiology of the hearing organ itself and of variation in central auditory plasticity. While speech perception is a critically important driver, the very nature of the cochlear implant itself, a medical device that typically includes ~22 small platinum ring electrodes < 400 μm diameter, distributed along the length of the cochlea is limiting with respect to the ability to finely recruit spiral ganglion neurons. In normal hearing, the cochlea provides tonotopic mapping, where progressively lower frequency sounds are location mapped from the base to the apex of the spiralling structure, encoded by spiral ganglion nerve fibres. If the neural interface with the cochlear implant electrodes can be improved, then hearing performance with the device will be enhanced.