RESUMEN
BACKGROUND AND OBJECTIVES: Many people have been concerned about voice change after laser assisted uvulopalatoplasty (LAUP). A number of studies reported acoustic changes after uvulopalatopharyngoplasty (UPPP) and LAUP. However, there have not been any reports on the association between anatomic change and acoustic results after LAUP. The purpose of this study is to analyze changes in the voice and changes in the vocal tract after LAUP and to evaluate whether the anatomical changes of vocal tract have an effect on the voice change or not. SUBJECTS AND METHOD: By using CSL, we analyzed fourteen LAUP cases on the formant frequencies of six vowels (/a/, /i/, /u/, /=, /o/, /e/) and four nasal consonants (/hana/, /eomma/, /eoungga/, /chiken/). By using MR image, we analyzed changes in the vocal tract eight weeks after LAUP with preoperative findings in three cases. RESULTS: In acoustic analysis, the second formant frequencies of /u/ and /= phonation were significantly reduced postoperatively compared to those of preoperative status. In imaging study of /u/ and /=, the uvula and soft palate were contracted, so coupling was occurred between nasal cavity and oropharynx in /u/ and /= phonation and the tongue was shifted toward posterior pharyngeal wall to compensate coupling. CONCLUSION: LAUP reduced the second formant of /u/ and /=, which did not result in serious voice changes.