Visible/tactile vowel information to be transmitted to the hearing impaired

Abstract

A new method to evaluate visual/tactual systems for the hearing impaired has been proposed and quality of vowel information to be transmitted has been discussed. In this method with synthetic vowels, three fundamental abilities which indicate categorizing a large number of stimuli, normalizing male/female voice and compensating for coarticu-lation effect are tested and evaluated in comparison with normal auditory abilities. According to the results obtained by applying the testing method to two visual and two tactual systems, both visual systems can present much better vowel information than it by the tactual systems in the sense that a large number of vowels different in the formant frequencies are correctly categorized. Furthermore, the visual system (V-color) only which converts voiced portions of connected speech into color pictures on a TV screen transmits information available in normalizing male and female voice and in compensat-ing for coarticulation effect to be appeared on connected vowels. It is considered that strict evaluations on goodness of information give a guide to the development of new aids.