Abstract
Among neural prostheses cochlear implants (CIs) are considered the most successful devices. They restore some hearing to ~210,000 severe-to-profound hearing impaired people. Despite the devices’ success, the performance of the implanted individuals in noisy environments is poor and music perception is rudimentary. It has been argued that increasing the number of independent channels for stimulation can improve the performance of a CI user in challenging hearing environments. An optical method, stimulating neurons with infrared radiation, has been suggested as a novel approach to increase the number of independent channels. Infrared neural stimulation (INS) works through the deposition of heat into the tissue. Thermal damage is therefore a potential risk, particularly for longterm exposure. To verify the efficacy and safety of INS, cats were implanted for about 4 weeks and were continuously stimulated daily for 6-8 hours. Cochlear function did not change during the stimulation, and histology did not reveal signs of damage. Tissue growth following the implantation was largely localized at the cochleostomy.
