This work is aimed at developing two new tactile aids for the deaf. Tactile aids transduce acoustic signals for display as vibratory patterns on the skin and can be appropriate assistive devices for some deaf persons who receive no benefit from cochlear implants or hearing aids. Tactile aids provide oral communicators with a speech signal that supplements lipreading, and all users with useful signals associated with environmental sounds and music. Currently, no tactile aids are commercially available for those deaf persons who can benefit from them. One of the new tactile aids to be developed in this project is specifically designed for use by infants. This device, which has the form of an arm-worn strap, is designed to be waterproof, small, and lightweight. For young deaf children awaiting a cochlear implant, this tactile aid may be an alternative to hearing aids that is more comfortable and convenient, as well as acoustically richer. The second tactile aid being developed is a wristwatch-type device for older children and adults. Both the infant and adult aids will have wireless microphones and signal processing that extracts low- and high-frequency envelopes for display on two vibrators. Work in Phase I produced a prototype tactile aid that can be comfortably worn on the arm by an infant or toddler. This prototype meets specified criteria for weight, water resistance, battery life, physical ruggedness, and stimulation level. Work in the first 15 months of Phase II will be devoted to refining the design of the infant aid and completing the design of the adult aid. Copies of these refined prototypes will be produced for six-month field trials with infant and adult users. Three clinical sites have agreed to cooperate in identifying candidates and in conducting the infant trial.
The aims of the trials will be to identify usability issues and to assess efficacy of the aids for both groups of users. For infant/child subjects, efficacy will be assessed with questionnaires addressed to the parents and audiologist covering such issues as responsiveness to sound and change in frequency and quality of vocalization. Adult users will be given tests to assess lipreading ability (when appropriate) and environmental sound recognition;they will also be questioned on their reactions to the device. It is the goal of the present work to update and expand the role of tactile aids in aural rehabilitation with improved, easier-to-use devices designed specifically for infants and adults.
This project to develop new tactile aids will fill a void in the array of devices that can be provided to assist speech communication, environmental-sound recognition, and music appreciation for some deaf persons. Although the size of the population of deaf persons who can benefit from tactile aids is small, it is a population for whom innovative technological assistance is greatly needed to support habilitation and independent living.