If you can’t use your ears to hear something, you might one day use your tongue.
Researchers at Colorado State University have developed a mouth retainer that translates incoming audio into electrical signals that pulse. Someone with hearing loss places their tongue against the guard and reads the pulse like it was Braille on their fingertips. The process is similar to the way the cochlea works in a fully hearing person, but instead of stimulating nerve cells in the ear, the device stimulates them in the tongue.
The device could be a cheaper alternative to cochlear implants that bypass a damaged ear and send signals directly to the auditory nerve. Implants can cost up to $100,000, and involve surgery. “The idea is that this device would much more affordable and less invasive than an implanted device. It could be taken in and out like a dental retainer and would be about the same size,” says JJ Moritz, a graduate student working on the project.
The retainer contains about 20 electrodes, each of which pulse 30 to 100 times per second in different ways. That leaves plenty of ways to communicate.
Moritz and his colleagues have a prototype, but still need to finish “mapping the tongue” to understand how each person reads the electrical signals. “We’re starting to get an idea of how much variability there is between the location of nerve endings on different peoples tongues,” Moritz says. “We have enough data to design customized devices for individuals but we do not have enough data for generic devices that will work well for many people.”
As with braille, learning to read with one’s tongue might take time. The CSU team is planning an internal study now, and hopes to test the device publicly before the end of 2015.