Perception of Formant-emphasized Vowels by Hearing Impaired Children

Abstract

In order to solve the confusion of Japanese vowels, experiment of perception on vowel /i/, /e/, /u/ was conducted by emphasizing the first and second formant. In acquired deafness confusion was reduced by the emphasis of second formant. Improvement by emphasis of the first formant was observed only at vowel /u/.
In four hearing impaired children, two of them had audiometric configurations of “flat” type and the others had “sharp cut” type. The results in four hearing impaired children were followings:
1) In the subject with the “flat” type hearing loss, improvement of vowel confusion was observed by emphasis at the second formant.
2) In the subjects with “sharp cut” type, improvement of vowel confusion was observed by emphasis at first formant.
In the subjects with “flat” type, the effects of up-ward spread masking to the second formant was considered as the results of emphasis of the first formant. But those effects couldn't explain the results from the first formant emphasis in the subjects with “sharp cut” type.