A new low-power signal-processing chip that could lead to a cochlear implant that does not require external devices has been developed by researchers at MIT’s Microsystems Technology Laboratory (MTL), together with physicians from Harvard Medical School and the Massachusetts Eye and Ear Infirmary (MEEI).
The chip uses the natural microphone of the middle ear rather than a skull-mounted microphone. The implant would be wirelessly recharged and would run for about eight hours on each charge.
Existing cochlear implants require patients to have a disk-shaped transmitter about an inch in diameter affixed to their skull. That device inductively links with a matching device implanted under the skin, which attaches to wire that connects to the cochlea.
There’s also a microphone/power source that looks like an oversized hearing aid mounted around the patient’s ear.
The MIT researchers’ new design removes all of the external components and exploits the mechanism of a different design: a “middle-ear implant.” Delicate bones in the middle ear, known as ossicles, convey the vibrations of the eardrum to the cochlea, the small, spiral chamber in the inner ear that converts acoustic signals to electrical.