Objective: To study the acoustic-phonetic features of the cleft patients with marginal velopharyngeal closure.
Methods: The acoustic-phonetic features of 17 cleft patients with marginal velopharyngeal closure were analyzed with USSA sound spectrograph, contrasted by the features of 28 cleft patients with velopharyngeal incompetence and 18 patients with velopharyngeal competence.
Results: The manifestations of single vowel spectrum differ from that of the same vowel in sentence for MVPC patients. There are extra formants or strong nasal formants in a number of vowels spectrums in sentence, while they do not occur on single vowel spectrum. The spike and stop gap in the spectrograms of stops and affricatives may be absent or existing occasionally, and the noise energy in the lowest frequency area in the spectrograms of aspirated consonants may be watched or not.
Conclusion: Acoustic analysis is very valuable to evaluate the state of marginal velopharyngeal closure. Analyzing the acoustic features of multiple vowels and consonants, and comparing the resonance characteristics of single vowel with the same vowel in continuous speech simultaneously are emphasized.