A device that lets deaf people hear with their tongue

January 21, 2015 16:11
CSU researchers (from left) Dr. John Williams, Dr. Leslie Stone-Roy and graduate student JJ Moritz show how the device works. Photo: Gizmag

It's quite crude at the moment, but researchers at Colorado State University are developing a device that will allow hearing-impaired people to hear using their tongue.

At the moment, many who are deaf prefer cochlear implants to regain their sense of hearing. But such a device is not only expensive but also involves surgery. Besides, it doesn't work on all forms of hearing loss.

According to technology website Gizmag, cochlear implants use a microphone placed adjacent to the ear to receive sound waves. The sounds are filtered through a speech processor which picks out human speech. The speech sounds are then converted into electical impulses, which are transmitted to a series of electrodes implanted in the cochlea. The electrodes stimulate the auditory nerve, thereby delivering sound information to the brain.

The device being developed by the CSU team led by Prof. John Williams works in a similar fashion, except that the retainer is placed in the mouth.

It also uses a microphone-equipped earpiece to pick up sounds which are then converted into electrical signals. The signals are sent by Bluetooth to the retainer, which the user holds in their mouth. When they press their tongue up against the device, the electrodes in the device respond to the received signals by selectively stimulating nerves in different parts of the tongue, Gizmag says.

After a period of training, the user can learn to associate specific patterns of "tongue tingles" with specific.

But why the tongue? That's because the taste organ contains thousands of nerves, and the region of the brain that interprets sensations from the tongue is capable of decoding complex information.

It's something like the Braille system, which allows blind people to run their fingertips across bumps on the book and interpret them as letters and words.

Unlike a cochlear implant, the CSU system requires no surgery and is a lot cheaper. Users also don't need to have functional auditory nerves to be able to "hear".

However, much work still needs to be done on the device. The CSU researchers are still mapping out the nerves in the tongue to determine which areas are most receptive to stimulation.

Also, there's the inconvenience of having to put the device in the user's mouth every time it is to be used, not to mention hygiene and safety issues.

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