Toward optogenetic hearing restoration

When hearing fails, cochlear implants (CIs) provide open speech perception to most of the currently more than a million CI users. CIs bypass the defective sensory organ and stimulate the auditory nerve electrically. The major bottleneck of current CIs is the poor coding of spectral information, which results from wide current spread from each electrode contact. As light can be more conveniently confined, optical stimulation of the auditory nerve presents a promising perspective for a fundamental advance of CIs. Developing optogenetic stimulation for auditory research and future hearing restoration requires efforts toward development and characterization of appropriate channelrhodopsins, their viral gene transfer to cochlear neurons, as well as medical device engineering. The presentation will summarize the current state of the art and plans for developing gene therapy of the auditory nerve and optical CI as well as their combination for improved hearing restoration by optogenetic sound coding.