Responses from single units in the dorsal cochlear nucleus to electrical stimulation of the cochlea

Abstract

An aim of the electrical stimulation strategy of a cochlear implant is to mimic the response of the auditory system to acoustic stimuli, so that hearing sensations generated by the implant can be recognisable and useful to the implantee. To help improve our understanding of how the brain responds to electrical stimulation of the auditory nerve we have examined the responses of dorsal cochlear nucleus (DCN) units to both acoustic and electrical stimulation of the cochlea in a hearing animal. This work extended our previous studies which have compared the responses to electrical and acoustic stimulation in the auditory nerve [1] and the ventral cochlear nucleus [2].

Our studies addressed two questions: (1) What are the responses of DCN units to electrical stimulation of the auditory nerve? (2) Was it possible to identify acoustic and electrical stimuli which generated similar responses from individual DCN units?

By answering questions 1 and 2, it may be possible to deduce the electrical stimulus parameters which should be employed in cochlear implant speech processing strategies to mimic acoustic-like responses from neurons of the dorsal cochlear nucleus. The generality of observations from the cochlear nucleus could then be tested at other nuclei within the central auditory pathways.