[The influence of pharyngoplasty on articulation]

Pharyngoplasty is a surgical technique for the treatment of obstructive sleep apnea and snoring. The most commonly employed pharyngoplasty technique is uvulopalatopharyngoplasty (UPPP). The anatomical structure of the pharynx is usually changed in this procedure, and a change in articulation may result, because the pharynx plays a important role in articulation. We, therefore, assessed the influence of pharyngoplasty on articulation in patients who underwent UPPP. Perceptual study: Twenty-five Japanese monosyllables uttered by 12 patients were tape-recorded pre-and postoperatively. The results of listening tests showed no significant changes in articulation scores for any syllables in the pre-and postoperative samples, and there were no nasalized articulations and no reduced intensity of consonants. Acoustical study: The first and second formant (F1, F2) of the five Japanese vowels pronounced by 20 patients were recorded pre-and postoperatively. In addition, intraindividual variation in the F1, F2 of the five Japanese vowels were measured in 4 normal subjects. The F1 and F2 of the vowel /e/ were slightly higher postoperatively. F2 of vowel /u/ was slightly lower postoperatively, and the F2 of vowel /o/ showed the same change. These changes in formants, however, fell within the range of intraindividual variation.

There is no problem in the articulation of phonemes after UPPP, but the timbre of the voice may be influenced by the changes in formants.