About ten years ago, some electrical engineers showed how ya can see with yer tongue. They built an array of electrostimulators and connected it up to a camera. Put the array on your tongue and it provides a pattern of stimulation that matches the pattern of light hittin the camera. This Tongue Display Unit turned out to be almost useful for people with impaired vision.
Now Nicolas “Girls” Guillerme at Laboratoire TIMC-IMAG in Grenoble is usin’ the same ah-dear to improve balance. Instead of an image, the Tongue Display Unit provides feedback about orientation which the wearer can use for balance. Nicolas Girls has already tried out the device on people with their eyes closed and says it helps (although there are so few in the study that there ain’t no tellin whether it’s helpful or not).
Now he wants to see whether it can help diabetics who have lost feeling in their legs and so have trouble balancing. Just don’t ask em to talk with their mouths full.
Ref: arxiv.org/abs/0709.0689: A Plantar-pressure Based Tongue-placed Tactile Biofeedback System for Balance Improvement