Articulation after uvulopalatopharyngoplasty.

We performed perceptual and acoustic studies to demonstrate articulation after uvulopalatopharyngoplasty (UPPP) in Japanese patients at 28.6 days (mean) after surgery (range 21-50 days). The results of listening tests showed that there were no significant changes between pre- and postoperative articulation scores for any of 25 monosyllables tested, and there were no significant changes in the timbres of 5 Japanese vowels after UPPP. In the acoustic study of the first and second formant frequencies of the vowels, some formant frequencies had significant changes after UPPP. However, these changes in formants fell within the range of intraindividual variation. In the acoustic study of /ka/ with a palatal plosive /k/, there was no significant change in the voice onset time or F2 transition after UPPP.