Drew,
With respet to cochlear implants, the internal implanted processor uses no batteries. It gets its power from the RF signal transmitted through the scalp via the external processor. The external sound processors have batteries that are different physical sizes and thus last different lengths of time. They have adapters that are worn on a belt for example and use standard disposable batteries.
There are several different types of external processors. Some are worn on the ear like a hearing aid and are called BTE (behind the ear)....then there are those that can be worn on a clip to a shirt collar or belt, or such.
Most are extremely water resistant and Advanced Bionics is about to release one that is water proof.
The BTE batteries are extremely expensive, rechargeable but some users have had 7 years of use from them and they are still functioning fine.
The devices are extremely expensive but are covered by insurance and Medicare.The cost can go from $65,000-$90,000.
It is an important enough decision that I would recommend everyone do their own research and decide which one of the 3 FDA approved brands is right for them. Each uses a different method to achieve results. IMHO it's important enough that each individual be convinced they have the best product for them. I may not agree with you.....you may not agree with my selection. That doesn't matter. Even if it is just a placebo effect, it's important that I believe I chose the best one for me and you believe you chose the best one for you. That's what's important. Of course reliability is important too but all 3 of the FDA approved brand products have extremely good reliability records.
It's important to understand the difference between a cochlear implant and the "Esteem" device to which Mike referred. The Esteem device replaces defective bones in the middle ear....the stirrup, anvil and hammer. This type of device relies on the patient having a normally functioning inner ear including a cochlea.
A cochlea implant replaces a defective cochlea. An internally implanted processor has an antenna, a processor with electronics and a cable with electrodes. The processor/antenna are implanted under the skin while the cable with the electrodes are inserted via a small hole into the snail shaped cochlea. Within the antenna/processor is a rare earth magnet.
The external sound processor looks like a hearing aid processes sounds digitizing it and modulating an RF signal with it. The modulated signal goes via a cable to an antenna. This antenna has a rare earth magnet that attachés this antenna to the one under the skin of your scalp. Some of the RF is stripped off and converted to DC voltages to power the internally implanted processor (That's right no battery under your skin). The implanted processor converts the digital sounds to analog excitation currents and stimulates the auditory nerves. This in turn sends electrical stimulations to your brain to be interpreted as sounds.
Pretty complex and somewhat a miracle. And if I am one of the lucky....I'll be happy as one can be. It can take up to 2 years to retrain the brain to recognize these new stimulations as sounds. I am optimistic but I have one foot on the ground realizing that it will take a lot of work on my part and I could fall in that group of less than 1% that CIs don't help. Am I making sense?
