Opto-electrical Cochlear Implants

Brief Summary

Neural stimulation with photons has been proposed for a next generation of cochlear implants (CIs). The potential benefit of photonic over electrical stimulation is its spatially selective activation of small populations of spiral ganglion neurons (SGNs). Stimulating smaller neuron populations along the cochlea provides a larger number of independent channels to encode acoustic information. Hearing could therefore be restored at a higher fidelity and performance in noisy listening environments as well as music appreciation are likely to improve . While it has been demonstrated that optical radiation evokes auditory responses in animal models, it is not clear whether the radiant exposures used in the animal experiments are sufficient to stimulate the auditory system of humans. The proposed tests are: 1. to demonstrate that light delivery systems (LDSs) can be inserted and oriented optimally in the human cochlea. 2. to show that the LDSs are able to deliver sufficient amount of energy to evoke a compound action potential of the auditory nerve. 3. to validate that the fluence rate (energy / target area) required for stimulation is below the maximal fluence rate, which damaged the cochlea in animal experiments. 4. to show that combined optical and electrical stimulation is able to significantly lower the threshold required for optical stimulation in humans. The endpoints for the study are either the completion of the experiments proposed or the demonstration that not sufficient energy can be delivered safely in the human cochlea to develop an action potential.