ACOUSTIC CHANGES IN VOICE AFTER TONSILLECTOMY

The vocal tract from the glottis to the lips is considered to be a res onator and the voice is changeable depending upon the shape of the voc al tract. In this report, we examined the change in pharyngeal size an d acoustic feature of voice after tonsillectomy. Methods: Subjects wer e 20 patients. The distance between both anterior pillars (glossopalat ine arches), and between both posterior pillars (pharyngopalatine arch es) was measured weekly. For acoustic measurements. the five Japanese vowels and Japanese conversational sentences were recorded and analyze d. Results: The distance between both anterior pillars became wider 2 weeks postoperatively, and tended to become narrower thereafter. The d istance between both posterior pillars became wider even after 4 weeks postoperatively. No consistent changes in F0, F1 and F2 were found af ter surgery. Although there was a tendency for a decrease in F3, tonsi llectomy did not appear to change the acoustical features of the Japan ese vowels remarkably. It was assumed that the subject may adjust the shape of the vocal tract to produce consistent speech sounds after the surgery using auditory feedback.