The implications of the tadoma method of speechreading for spoken language processing

Strong support of the capacity of touch as a communicative sense is provided by the Tadoma method of communication. Through this method, individuals who are deaf-blind have been able to acquire a full range of spoken language abilities. In the Tadoma method, direct contact is made between the hand of the deaf-blind receiver and the face of a talker to monitor the various articulatory actions that occur during speech. Studies conducted with a group of experienced deaf-blind practitioners of Tadoma have documented their abilities for speech reception, speech production, and linguistic competence. The results of this research indicate that individuals who suffered deaf-blindness in early childhood (e.g., around 18 months of age) can understand speech produced at slow-to-normal rates with reasonable accuracy, can produce speech that is reasonably intelligible to many listeners, and have an extensive command of English that compares favorably in many areas to that of hearing individuals. The performance of these deaf-blind individuals implies the adequacy of the tactual sense to support the development of speech and language and thereby provides a strong impetus for continued research on the development of sensory-substitution devices for spoken language processing. Current efforts on the development and evaluation of artificial tactile devices for speech communication will be discussed.