Development of a vowel corrector for the deaf.

The development of a visual speech apparatus that gives information about the identity of vowels spoken in a CVC context is described. The principle of the apparatus is based on a dimensional analysis of the vowel spectra. In developing the device, the demands of the specific speech correction setting of the deaf were taken into account as much as possible. From a number of physical and statistical analyses of vowels in different consonantal surroundings, it appeared possible to separate two vowels quite sitisfactorily. In describing the apparatus, special att~ention is given to some technical features that were added to satisfy the requirements of speech correction. Finally, the operation of the device is tested with a large number of monosyllables pronounced by 20 speakers. The results indicate that the apparatus satisfies the conditions stated for practical use.