Otologics, of Boulder, CO have developed hearing aids which are practically invisible. I know you are wondering that if they are invisible then how they work. Actually they are fully implantable device that will soon change the world of hearing loss. Millions of people wear hearing aids which have made life comfortable for them. However these aids have some limitations like hearing impaired can't wear them while showering or swimming and most models are hard to wear while sleeping. But the new kind of hearing aid will overcome these problems. It's invisible and waterproof because all of its circuitry including its battery and microphone is in the user's head. A survey has also found out that the device not only improved their hearing, but also sounded more natural than their old hearing aid. The only problem is that are all these benefits worth taking the risk associated with required surgery. Now that’s the call the user has to take.

The device is powered by a battery that is recharged when the user places a small radio transmitter against the head for 60 to 90 minutes. An inductive coil in the implant converts the radio energy to electricity and recharges the battery with it. The battery can stay inside the body for at least five years, according to the company, before it needs to be replaced.
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