Tonsillectomy is a surgery commonly performed for treating repetitive tonsillitis. Tonsillectomy changes the shape and characteristics of the pharynx. It could also alter the resonating characteristics of the pharynx and affect the voice of the patient. We examined the voice changes in patients undergoing tonsillectomy.
A total of 33 adult patients who underwent tonsillectomy at our institution between July 2020 and December 2021 were included in the study. The subjects consisted of 16 males and 17 females, with a mean age of 33.7 ± 10.7 (mean ± SD) years. We measured the maximum phonation time, acoustic analysis values (Jitter%, Shimmer%, NHR), speaking fundamental frequency, and vocal range, first four formants (F1 to F4) in the sustained vowel /a/, and VHI. We examined whether there were any changes at 3 months after the surgery as compared with the findings prior to the surgery.
The shimmer% and NHR decreased significantly after surgery as compared with the observations prior to surgery. In the female patients, the speaking fundamental frequency tended to increase and the F2 significantly increased after the surgery as compared with that prior to surgery.
Removal of the swollen tonsils reduced the resistance of the supraglottic space and resulted in a lower laryngeal adduction force required for phonation. The decrease of the shimmer% and NHR might be attributed to reduction of the turbulence in the supraglottic space. The change in the shape of the pharynx caused the changes of the speaking fundamental frequency and formants. The changes were thought to be influenced by the size of the patient’s pharyngeal cavity, the volume of the tonsils, and the scarring of the pharyngeal mucosa. It is important to inform patients before the operation about the possibility of changes in their voice after the operation.
