Frank A. Saunders

Seeing with the skin

A system for converting an optical image into a tactile display has been evaluated to see what promise it has as a visual substitution system. After surprisingly little training, Ss are able to recognize common objects and to describe their arrangement in three-dimensional space. When given control of the sensing and imaging device, a television camera, Ss quickly achieve external subjective localization of the percepts. Limitations of the system thus far appear to be more a function of display resolution than limitations of the skin as a receptor surface. The acquisition of skill with the device has been remarkably similar for blind and sighted Ss.

Electrocutaneous Stimulation for Sensory Communication in Rehabilitation Engineering

Physiological and psychophysical functions underlying electrocutaneous stimulation are discussed, including a comparative review of stimulus parameters and coding formats. Procedures are recommended for implementing electrotactile displays and for generating reliable, painfree sensations with a useful communications bandwidth.

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.

A wearable tactile sensory aid for profoundly deaf children

A field evaluation was conducted in a classroom for profoundly deaf children, to determine the effects upon speech production of experience with a tactile sensory aid. The aid displays sound frequencies as touch patterns on a belt worn around the abdomen.

A tactile vision substitution system.

ABSTRACT A prototype of a tactile television system has been developed, in which a television camera image is projected onto the skin of the back by means of vibrating electromechanical stimulators. Blind subjects, within a few hours of training, have learned to identify geometric forms, movement in depth, environmental objects, photographs of faces, and block letter words.

Speech perception via the tactile mode: Progress report

A wearable twenty-channel electrotactile vocoder was used to transform audio speech stimuli into tactile patterns via a linear display on the abdomen, analogous to a frequency-to-spatial transform with increased resolution in the F2 region. A two-choice discrimination task, with simultaneous auditory and tactile feedback, was used to train and test hearing subjects on the tactile discrimination of monosyllabic words having minimal phonemic differences. In subsequent studies, the perception of words embedded in sentences and in connected discourse was tested. Results, and implications for the processing of speech information via the tactile mode, will be discussed.

Field tests of a wearable 16‐channel electrotactile sensory aid in a classroom for the deaf

Field testing of a wearable electrotactile sensory aid began in February 1985 at the Jackson Hearing Center, an oral program for deaf children in Palo Alto, CA. Six children, 3 to 8 years of age, participated in the study. Each had a profound congenital binaural sensorineural hearing loss in excess of 105 dB. The wearable sensory aid, the Tacticon model 1600, presents 16 channels of frequency information via a tactile belt worn around the abdomen. Wearing time for each child was gradually increased from half‐hour daily lessons to 4 h of use per day. Environments included the classroom, outside recess with physical education activities, and field trips. Receptive training was directed at recognition of both suprasegmental and segmental features of speech. Suprasegmental features included duration, number of syllables, rhythm, and stress. Segmental features included the recognition of specific speech sounds in isolation, beginning with the Ling 5 sound test of /a/, /e/, /u/, /s/, and /sh/. The assessment pr...

Development of a Plato-Based Curriculum for Tactile Speech Recognition

This project has initiated the development of a PLATO-based curriculum, teaching profoundly deaf children to understand speech sounds which are presented as touch patterns on the abdomen. In a unique and innovative process, PLATOs auditory disk output is used to “speak” words and phrases, which in turn are converted to touch patterns via a new sensory aid, the teletactor. This aid presents sound information as flowing, dynamic patterns on the skin, which are learned like a new language. PLATO, presenting words and phrases via the teletactor, accepts and judges the students responses in interactive practice and testing. The curriculum utilizes PLATO (a) as a computer-assisted language learning system; (b) as a multimedia interactive communication system; and (c) as a computer management system for psycholinguistic experimentation, evaluation, and statistical analysis.

Speech perception via the tactile mode: A progress report

Research is in progress to determine the extent to which hearing subjects can learn to process speech presented only in the tactile mode. This approach extends the theoretical ccncepts of sensory substitution to the area of profound deafness. A 20‐channel tactile vocoder was used to transform audio speech stimuli into tactile patterns on a belt worn on the abdomen. The tactile transform is analogous to a frequency‐to‐spatial transform with increased resolution in the F2 region. A two‐choice discrimination task, with feedback, was used to train and test hearing subjects on the tactile discrimination of monosyllabic words having minimal phonetic differences. After responding to each stimulus, subjects received simultaneous tactile and auditory feedback. Results from this study and from subsequent research will be presented.

The effect of a wearable 16‐channel electrotactile sensory aid on receptive communication skills of profoundly deaf children

Six children, 3 to 8 years of age, with profound congenital binaural sensorineural hearing losses were fitted with a wearable elecrotactile sensory aid, the Tacticon, in March 1985. Their receptive skills for both speech and environmental sounds were evaluated using a battery of selected tests. Following a 9‐month training period, a comparison was made of their scores in the following conditions: (1) pre‐ and post‐test auditory only (with hearing aids); (2) pre‐ and post‐test auditory/visual (hearing aids and speechreading); and (3) post auditory/tactile (hearing aids and Tacticon) and auditory/visual/tactile (hearing aids, speechreading, and Tacticon). All the children were able to integrate information delivered simultaneously by the auditory, visual, and tactile senses and their scores were consistently higher when wearing the Tacticon than in the comparable condition without the tactile aid. A modified “tracking” procedure was used to determine the amount of time required to correctly identify spoken ...