Objectives: The aim of this study was to evaluate changes in acoustic features of speech and voice after tonsillectomy with or without adenoidectomy.
Methods: Before and 1 month after surgery the following parameters were estimated: average of fundamental frequency (Fo), Jitter percent (Jitt), Shimmer, noise-to-harmonics ratio (NHR), voice turbulence index (VTI), soft phonation index (SPI), degree of voiceless (DUV), degree of voice breaks (DVB) and peak amplitude variation (vAm); as an evaluation of nasal resonance, speech articulation and voice handicap index (VHI).
Results: The results were statistically evaluated using the unpaired t-test. Probability values below 0.05 were regarded as significant. One month after surgery, our data showed significant (P<0.05) improvements of the acoustic and other parameters in the children submitted to adenotonsillectomy: Fo (176Hz vs. 206Hz, after sustained vowels: 206Hz vs. 192Hz; 148Hz vs. 168Hz; 171Hz vs. 161Hz after balanced sentences), Jitt (0.85% vs. 1.81% to 0.82% vs. 1.81%), Shimmer (3.41% vs. 5.81% to 4.89% vs. 5.73%), NHR (0.16 vs. 0.42 to 0.29 vs. 0.39), VTI (0.05 vs. 0.38 to 0.28 vs. 0.37), SPI (14.78 vs. 21.14-19.89 vs. 21.89), DUV (0% vs. 0.44% to 0% vs. 0.48%), DVB (0% vs. 0.42% to 0% vs. 0.42%) and vAm (8.93% vs. 23.89% to 8.89% vs. 24.25%).
Conclusions: The results suggest the role of adenotonsillectomy in the improvement of voice and speech quality and of objective evaluation of speech and voice in the correct management of these children.