Pinhead-Sized Implant Could Replace Hearing Aids

An anonymous reader writes "Depending on the level of hearing impairment, conventional aids may not be good enough and a hearing implant is the only option. Until now the required surgery to fit them has taken several hours. However, that is about to change. A new implant that can be fitted with outpatient surgery has been developed consisting of a 1.2mm electro-acoustic transducer, which is positioned at the so-called 'round window,' which is where the middle and inner ear connect. It then produces amplified mechanical vibrations that stimulate the auditory nerve. Even though the transducer is tiny, it can reach volumes of up to 120 decibels."

Comments

not ready for prime time, still just parts

[girlinatrainingbra]

Cochlear implants are required for some deaf patients, and those are the implants that require surgery. This PR bulletin from the Fraunhoffer institute is very cool, but it's like the retinal implants for vision, actually it's not even up to the level of retinal implants which are at least currently being tested. This implant system only has had its individual parts created.
.
Those individual components have not yet been put together to make a full hearing aid. This is just a proof of concept or feasibility study thus far. They still have to select the materials that will be used for the long term implantation. An assembled version may be ready next year. As for the extremely small size claimed, that small size is just for the "electroacoustic transducer" (the details in the PDF file says it's a piezoelectric micro-actuator). And the round window is already the part of the ear that bulges in and out as the oval window accepts input from the stapedius. So this adds pressure on the other side of the fluid column. Experts are currently testing a first working prototype in the laboratory. Results have been positive to date. "The individual components of the hearing aid have all been developed. The next step is to optimize and assemble them," says Kaltenbacher. The implant must measure up to high requirements: the material must be encased so the body tolerates it and it has to remain stable over long periods -- after all, hearing aid implants should last at least ten years. The optimized individual components should be ready by June of this year; testing of the overall system is planned for 2014.

Re:not ready for prime time, still just parts

[Vintermann]

It's still interesting news, and good news. I knew an early cochlear implant user who had become deaf as a result of meningitis. He was stuck with a poor first generation implant - they were not exactly easy to upgrade.

Re:not ready for prime time, still just parts

[ozydingo]

For 1, my best guess is that energy comes from an external transducer, coupled to a coil of the implant that can drive the actuator. Cochlear implants use this strategy (except they drive electrical impulses, not mechanical vibration)

Both 2 and 3 are handled by an external dsp. The implant piece is just the final acoustic amplifier / transducer; it is not driven by acoustical energy entering the ear, but by the signal being sent to it by the external device.

Keep Going

[Anonymous Coward]

Having severe hearing loss in one ear, this is very interesting to me, but honestly I would rather wait for results on current studies looking into regenerating damaged hair cells before pursuing this. The headline "Regaining Proper Hearing at Last" is in my opinion not quite correct; from what I can tell, they're just tickling whatever cells are left to stimulate harder than before, as opposed to restoring the full capability of input. Then you've still got signal processing issues like phase discrepancies, gaps in frequency coverage that need to be made up by transposing or saturating neighbor/harmonic frequencies, and all sorts of related hairy business. A big advantage here is you can break out the processing to a box with beefier DSP than you could fit in a BTE device, with batteries that last longer.

Definitely a step in the right direction, and by far better than similar solutions in the past, but still a long way from perfect.

Re:Keep Going

[ozydingo]

The hair cells are inside the inner ear, later in the signal path than this device, and are responsible for turning the mechanical stimulus inside the inner ear into electrical signals. This device bypasses the outer ear and middle ear (depending on the placement of the microphone). Bypassing the hair cells means directly stimulating the auditory nerves, e.g. with electrical impulses such as is done by current cochlear implants.

Also, analog amplification does not imply no signal loss even within its 120 dB operating range (due to noise, nonlinear behavior, etc etc). It is also practically a guarantee that any end-product using this device will employ dynamic range compression, among other things, that will result in further loss of information in the signal. Regardless, it is still likely that the signal will amplified digitally by the external dsp, then transmitted finally as an analog signal to the implant. However that's not in the scope of this research, which focuses on the implanted device (just the final acoustic amplifier, one of many parts of a hearing aid system).

(Sorry, I don't mean to be such a downer...)

Re:I'll take one to cure my tinnitus!

[Anonymous Coward]

Here's an odd thing about tinnitus -- I've been deaf in my left ear since age 5 from the mumps. As I understand it, the swelling suppressed the blood supply long enough to damage or kill the auditory nerve. The ear mechanism is probably fine but I'm deaf for lack of a communication link to the brain. I have tinnitus horribly. Weird thing is, I perceive hearing it in BOTH ears. Go figure. Make me wonder if it's a phenomena of the brain center rather than damaged receptors.