Information transmission across the skin: high-resolution tactile sensory aids for the deaf and the blind

New techniques are described for implementing high-resolution communication interfaces to the skin, by direct electrical stimulation of the sense of touch. The psychophysical properties of these displays are summarized, and a practical application is presented: an electrotactile sensory aid for profoundly deaf children, which displays acoustic information on the skin of the abdomen, via a belt of electrotactile stimulators. The resulting tactile patterns provide cues for recognizing environmental sounds, enhance the accuracy of lipreading, and enable the child to monitor his/her own voice. The tactile patterns corresponding to sounds must be learned, much like acquiring a second language; substantial training and experience is required. Other applications are discussed, both for the rehabilitation of sensory handicaps and for tactile communication in general.