Uvulopalatopharyngoplasty changes fundamental frequency of the voice--a prospective study

The aim of the study was to find whether a muscle-sparing uvulopalatopharyngoplasty (UPPP) and tonsillectomy cause a measurable change in the voice. The fundamental frequency and the first two formants of five sustained vowels were measured before and nine (six to 15) months following operation. The operation consisted of tonsillectomy and UPPP with preservation of the musculature of the soft palate. All patients received a pre- and post-operative 12-canal polysomnography (level-I sleep study). No patient showed signs of any post-operative velopharyngeal insufficiency. Acoustic analysis showed a significant raising of the fundamental frequency of up to 10 Hz. There was also a lowering of the second formant in two of the five vowels. This was correlated with the volume of the excised tissue. The minimal changes will probably have no significance for those who place no special reliance on their voice, but the possible post-operative changes should be made clear to singers and those relying on their voice for professional reasons.