Cochlear implants — with no exterior hardware

A cochlear implant that can be wirelessly recharged would use the natural microphone of the middle ear rather than a skull-mounted sensor.

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Cochlear implants — medical devices that electrically stimulate the auditory nerve — have granted at least limited hearing to hundreds of thousands of people worldwide who otherwise would be totally deaf. Existing versions of the device, however, require that a disk-shaped transmitter about an inch in diameter be affixed to the skull, with a wire snaking down to a joint microphone and power source that looks like an oversized hearing aid around the patient’s ear.

Researchers at MIT’s Microsystems Technology Laboratory (MTL), together with physicians from Harvard Medical School and the Massachusetts Eye and Ear Infirmary (MEEI), have developed a new, low-power signal-processing chip that could lead to a cochlear implant that requires no external hardware. The implant would be wirelessly recharged and would run for about eight hours on each charge.

The researchers describe their chip in a paper they’re presenting this week at the International Solid-State Circuits Conference. The paper’s lead author — Marcus Yip, who completed his PhD at MIT last fall — and his colleagues Rui Jin and Nathan Ickes, both in MIT’s Department of Electrical Engineering and Computer Science, will also exhibit a prototype charger that plugs into an ordinary cell phone and can recharge the signal-processing chip in roughly two minutes.

“The idea with this design is that you could use a phone, with an adaptor, to charge the cochlear implant, so you don’t have to be plugged in,” says Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor of Electrical Engineering and corresponding author on the new paper. “Or you could imagine a smart pillow, so you charge overnight, and the next day, it just functions.”

Adaptive reuse

Existing cochlear implants use an external microphone to gather sound, but the new implant would instead use the natural microphone of the middle ear, which is almost always intact in cochlear-implant patients.

The researchers’ design exploits the mechanism of a different type of medical device, known as 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. In patients with middle-ear implants, the cochlea is functional, but one of the ossicles — the stapes — doesn’t vibrate with enough force to stimulate the auditory nerve. A middle-ear implant consists of a tiny sensor that detects the ossicles’ vibrations and an actuator that helps drive the stapes accordingly.

The new device would use the same type of sensor, but the signal it generates would travel to a microchip implanted in the ear, which would convert it to an electrical signal and pass it on to an electrode in the cochlea. Lowering the power requirements of the converter chip was the key to dispensing with the skull-mounted hardware.

Chandrakasan’s lab at MTL specializes in low-power chips, and the new converter deploys several of the tricks that the lab has developed over the years, such as tailoring the arrangement of low-power filters and amplifiers to the precise acoustic properties of the incoming signal.

But Chandrakasan and his colleagues also developed a new signal-generating circuit that reduces the chip’s power consumption by an additional 20 to 30 percent. The key was to specify a new waveform — the basic electrical signal emitted by the chip, which is modulated to encode acoustic information — that is more power-efficient to generate but still stimulates the auditory nerve in the appropriate way.


The waveform was based on prior research involving simulated nerve fibers, but the MIT researchers tailored it for cochlear implants and found a low-power way to implement it in hardware. Two of their collaborators at MEEI — Konstantina Stankovic, an ear surgeon who co-led the study with Chandrakasan, and Don Eddington — tested it on four patients who already had cochlear implants and found that it had no effect on their ability to hear. Working with another collaborator at MEEI, Heidi Nakajima, the researchers have also demonstrated that the chip and sensor are able to pick up and process speech played into a the middle ear of a human cadaver.

“It’s very cool,” says Lawrence Lustig, director of the Cochlear Implant Center at the University of California at San Francisco. “There’s a much greater stigma of having a hearing loss than there is of having a visual loss. So people would be very keen on losing the externals for that reason alone. But then there’s also the added functional benefit of not having to take it off when you’re near water or worrying about components getting lost or broken or stolen. So there are some important practical considerations as well.”

Lustig points out that the new cochlear implant would require a more complex surgery than existing implants do. “A current cochlear-implant operation takes an hour, hour and a half,” he says. “My guess is that the first surgeries will take three to four hours.” But he doubts that that would be much of an obstacle to adoption. “As we get better and better and better, that time will shorten,” he says. “And three to four hours is still a relatively straightforward operation. I don’t anticipate putting a lot of extra risk into the procedure.”

Topics: Signal processing, Low-power electronics


This new technology will change many lifes worldwide

congratulations !

MIT, thanks for continuously Making Innovative Technology !!!

Sign me up for clinical trials when they are ready!

Very exciting news. Anyone know if there is more information about this new technology, and maybe when/if it will be available?

This new technology bypass the cochlear implant or does this new technology need the cochlear implant to work?

No exterior hardware! Awesome!

This would simply be amazing to so many people. Finally being included in a group discussion. Not being run over by a scooter when you're on the bike. hearing when someone enters the house. I am sitting here with someone who'd gladly volunteer if needed.

Is there any way to get in touch with the researchers? I'm profoundly hearing impaired at 26 and looking at the inevitability of getting a cochlear implant (in the next 2-5 years), and I have some thoughts about this technology. I think the possibilities are awesomely exciting, but I have some concerns about a few things. I'd love to be able to get in touch with researchers or anyone involved in this project. Thanks!

and its about time. Looks like a great team with MIT, Harvard Medical School and Massachusetts Eye and Ear Infirmary working together to improve hearing levels for the deaf and those with a severe to profound hearing loss. The FDA should fast track this once the completed internal CI is tested and proved safe for human use. Good Job Everyone.

Could it also support Bluetooth or WiFi, or any RF signal?

I've been my 91-year-old mother's tech support for the three years she's been in a nursing home, and getting sound she could hear from her telephone, TV, and hearing aid has been an ongoing problem, especially given the presence of a roommate.

this is amazing

my 6 year old baby boy using hearing aid and we are planning to have cochlear implant in future so should we wait for this new implant with no exterior .

please suggest me as early as possible.

please tell we will it come in market waiting for this.

This is very exciting news! A fantastic plus not to have any external parts. Please let me know when this new CI technology will be available. Are we talking about a year or ten before it is approved and available to patients? Thank you to all the researchers working on this project.

This new technology is very exciting! I would love to be a part of clinical trials! Let's hope this technology is available soon.

My son said this is a dream come true.

I would really like to be informed when this completely implantable cochlear implant becomes available. My deafness is worse and hearing aids aren't helping much.

Dear All, I just joined this forum, I'm from Italy. I have a 17 year old daughter who suffers progressive hearing loss. Nowdays we are starting to consider a cochlear implant on here right side. Does anybody have any deeper details as to when this new technology will be available ?

No external hardware would be amazing. My one year old has a cochlear implant. It is so difficult to keep the headpiece on him and keep the processor attached. I hope he can get this when it comes out.

Hi... I recently went for all the test and MRI scan etc.. i have been given the approval to go for the cochlear implant.. but what bothers me is the wire connecting from the head to the piece behind ear.. Can't this be made "wireless" or connect via blue-tooth or infrared instead of a wire?

Hi All, I have another question, most of you will please excuse me for not showing a great knowledge.... Once you have a cochlear implant in your ear, could the system still allow a "marginal" functionality of your natural cholera ? In other words, in case your natural hearing is not completely knocked off, could you still maintain it after the surgery ?

This innovation is about conveinance not vanity. How lovely would it be to be able to have someone whisper in your ear and be able to hear? Or to swim in the ocean and hear without worring about your processeor? Or to not have a magnet implanted in your head with a wire that gets tangled in your hair? Or to be able to hear when sleeping? This will be fast tracked-NOT 10 years. We demand it!

when is this technology going to be available? why is it taking so long
to start?

Please provide update of this product. I'm looking for it

This new invention is very exciting. I would really like to be informed when this completely implantable cochlear implant becomes available!!

I Wonder, when it could be used? Because I'm a mum and I'm living Türkiye. Technology comes here for a long time last. My son 5 years old and I'd love to see him when he wokes at night for pee or nightmare, he just can tell me or ı could teach him how to swim or we can play for a long time when taking a shower or we can easily run, jump, walk when the rainy weather. Sorry my englih, I know a little. But you can understand me, understand my feelings. And Thank you a lot. Thank you very much.

When this new technology will be available for implant?

Just think of how we could fix or update this little nifty implant with a two way talk with mind reading software and take over someone by making them think what you want them to think or wreck their life excetra!! Like keep yelling in their ear leave your husband or you need to go out more often so we can get into your home when your gone! Individually harass a person you don't like or make them look like they are crazy so you can get rid of that person! This is already happening I read about it in a Individual harassment web site and in a gang, cult and narcissist information web site and gas lighting website, they do this to people they hate and the government won't intervene because that would make them guilty of criminal activity for not stopping this activity in the past already and murder and other stuff because it happened for years!
Our President need to get something on the outside of anyone's body who has one of these and there are hundreds of different that they can find out who is harassing people and using them for criminal activity not for the death so they can hear or for a real covert activity excetra!

We have a person who is a relative or friend to some neighbors we know and knows all about this stuff in the Neillsville and Marshfield Area, I hope he is not using this technology in a criminal way! Because if that ever gets found out he will be in some huge problems! Do they have Satellite technology to track this activity with these people or even hear if someone is using it to harass or use it in a criminal way? I hope they do cause it has been! Just think if you heard voices and did not know someone put this in you for a criminal activity or if you did suicide because you did not know who to talk to or explain what is happening! I heard it is something they can do in a dentist office with a implant that works almost the same way! It's a CELL PHONE IMPLANT TYPE MECHONISM that is put in the gums or under a tooth cap and then sound or your voice to them vibrates in your jaw to the inside of your eardrum and thus only you and the other person hears this goes totally covert like spy stuff and that is how they harass you and torment the person with the implant! IT's the same type of implant they use in Gang tattoos on their arms and other body areas! T Our President has to put laws about how this stuff is used, because it can turn out to be a deadly and sinful covert one two way internal secret harassment war and but it all ready has been for years! It's the SECRET our law enforcers don't want to talk about but the military needs to know about! I guess other countries use this as a way to talk all the time, but some others figured out how to muse it another way! I heard someone hacked the military and found this information and figured out how to use it for criminal activity!
They better read the National Center for Communication's. Laws on Electronic communications internally or where ever, because there is a $20.000 + fine everyday( And you pay ALL other fines and ALL other doctor bills also!) until you get the implant out of the victim be in internally Electronically harassed if they find out who put it in and OUR President ( President Obama : Bless his sole!) also has a law for electronic harassment now that these under cover criminals need to be read and understood!

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