Scientists have developed a piece of technology that allows people to 'hear' via the tongue.

The new device uses an earpiece that communicates via wireless technology with a plastic retainer in the mouth. Bypassing the ear, signals are sent via nerves on the tongue into the brain, where they are interpreted as sound.

The team behind the development believe it could prove a simpler and less invasive alternative to the cochlear implant, and will be effective on deaf people and people with less severe hearing loss. The new technology, which is being developed at Colorado State University in the US, uses the thousands of nerve endings on the tongue and the region of the brain that interprets touch sensations to decipher sound waves.

The earpiece, which sits behind the ear much like a conventional hearing aid, picks up sounds, which are then converted into electrical impulses. These are transmitted wirelessly to electrodes in the mouthpiece,
which fits over the top teeth like a retainer. When the tongue is pressed against the device on the roof of the mouth, a pattern of electrical impulses is felt as a tingling sensation. With training it is believed that the brain will learn to interpret the specific patterns on the tongue as sound.

John Williams, a professor of mechanical engineering, who is leading the team developing the technology, said: "It's much simpler than undergoing surgery and we think it will be a lot less expensive than cochlear implants. We think our device will be just as effective but will work for many more people. It could also help people with less severe hearing loss."