[Study of testing velopharyngeal function via the third formant frequency of Chinese vowels]

The value of the third formant frequency (F3) of Chinese vowels of 24 patients with cleft palate and 10 normal children was measured with computerized speech signal processing system (CSSPS), and the rates of velopharyngeal incompetence (RVPI) of Chinese vowels of normal children were quantitatively analyzed using nasopharyngeal fiberscope (NPF). The correlation analysis between the RVPI of vowels [i] [a] and their F3 value of normal group was made. The results showed: 1. The F3 value of Chinese vowels between patients with cleft palate was not significantly different (P > 0.05); 2. The value of F3 in Chinese vowels of normal children was significantly higher than those of patients with cleft palate except [a] (P < 0.05 or P < 0.01); 3. There were generally velopharyngeal incompetence (VPI), in children with cleft palate and velopharyngeal competence of vowels in normal children except [a]; 4. There was highly native correlation between RVPI and F3 in vowel [i], the correlation coefficient was -0.8775 (P < 0.001). It was concluded the F3 of vowel [i] may be one of the most important indices testing velopharyngeal function of postoperative children with cleft palate.