A computer-controlled vowel corrector for the hearing impaired.

The Vowel Corrector is a visual aid to be used in speech training of the hearing impaired. The display provides information about the identity of vowels spoken in isolation or in monosyllables. Vowels appear on a screen as differently located areas in a space, the coordinates of which are obtained from a dimensional analysis of vowel spectra. Resolving properties of the device, indexed by a measure of area overlap, are examined in detail. In particular, implications for differentiating utterances of male, female, and child speakers are studied. Results show that the device has promising features and is especially useful for exploring the vowel space as well as for learning a global differentiation of the vowels. The discrimination of spectrally similar vowels is limited, however. Ideas for future improvements are discussed.