Summary Clinical translation of optogenetic hearing restoration requires both, an efficient and safe gene therapy as well as a stable and powerful medical device. Working towards first in man trail, multichannel optical cochlear implant systems enabling long term evaluation of optical auditory nerve stimulation on behavioural level have been developed. Probing safety, stability and superiority of optical stimulation over available state of the art treatments, various animal models including non-human primates have been established. The presentation will focus on recent achievements in studies contributing to the regulatory process.