Researchers at Colorado State University are developing a mouth hearing aid that is effectively an electric retainer that transmits spoken words to users -- by buzzing their tongue. The device is an alternative to cochlear implants that are very expensive, have to be surgically installed and do not work on all forms of hearing loss.
The device uses a microphone-equipped earpiece to pick up sounds before converting them into electrical signals. These signals are then sent via Bluetooth to the retainer, which the user holds on their mouth. When users press their tongue against the device, the electrodes in them selectively stimulate specific parts of the tongue.
Users can be trained to associate specific patterns of tongue stimulation with given words. Since the tongue contains thousands of nerves, it is believed that this system could be used to help people with hearing impairments to process complicated words and information.