Non-invasive optical synthetization of hearing sensation in non-genetically modified animal

The last decade has seen discussions about applying infrared laser stimulation to brain–machine interfaces, such as cochlear implants, due to the capability of activating spatially selected neural populations without introducing exogenous agents to tissues. We established transtympanic laser stimulation, infrared laser irradiation of the cochlea from the outer ear, to reduce the invasiveness of surgical implantation by leveraging its contactless feature. Laser stimulation induces auditory perception in an intensity-dependent manner. Furthermore, the simultaneous combination of auditory and laser stimulation results in greater auditory perception than either auditory or laser stimulation alone. These findings suggest that laser stimulation can evoke and potentially enhance auditory perception, holding promise for implementation in auditory prostheses. Our work lays the groundwork for integrating transtympanic laser stimulation into auditory prostheses.