Progress in the development of a tactile aid for the deaf

Eight normal‐bearing adults learned to lipread with one of two lipreading aids. Both aids consisted of three spectral channels: a fixed high‐frequency and a midfrequency channel for sibilants and bursts and a low‐frequency channel for coding the first formant of vowels. Both aids relied on changes in sensation rather than locus of stimulation for transmitting spectral information and the amplitude‐time envelope. One aid had electrotactile and vibrotactile transducers and the other had only vibrators for transducers. Performance was measured with our “tracking” procedure (delayed shadowing) using ongoing text. Half the subjects performed the tracking task for the first four hours lipreading alone and the other half with one or the other of the aids. Aided subjects then changed to lipreading alone and unaided subjects to an aided condition. Results indicate that the aids can enhance tracking scores and can facilitate the learning of lipreading skills. [Supported by NS 03856.]