Some properties of formant frequencies of vowels uttered by deaf and hard of hearing children

Formant frequencies of the five Japanese vowels uttered by 35 deaf and hard of hearing children were measured utilizing sound spectrograph. The distribution of the formant frequencies on the F1-F2 plane for each kind of vowel and the relation between the formant frequencies of the five Japanese vowels of each of the defective children were compared with those of 8 normal children. Based on a muscle contraction model of speech organs, those results were analyzed in terms of the nature of imperfection in articulatory movement.