Assessment techniques to evaluate tactual aids for hearing-impaired subjects.

In order to optimize the use of tactual aids for the deaf, it is important to have a battery of assessments to determine the potential contribution of the aids to acoustic perception and speech identification. We have designed such a battery to be used with young hearing-impaired children. The tasks were developed so that they could be implemented with standard audiometric equipment and applied to subjects of varying age and to different types of tactual aids. Illustrative results from four profoundly hearing-impaired children showed that tactual vocoders allowed detection of high frequencies that were not available to the subjects through aided audition. In most cases with these subjects, performance on simple detection and discrimination tasks showed facilitative effects with tactual vocoders. Facilitative effects were further evidenced in more complex phonemic identification tasks for all subjects. The tasks can be used to determine possible benefits of tactual aids for individual hearing-impaired children.