Effects of unilateral vocal cord paralysis on objective voice measures obtained by Praat.

Unilateral vocal cord paralysis (VCP) affects the objective properties of voice by diminished neurologic control and degenerative changes in laryngeal tissue. The goal of this study was to compare the acoustic parameters of VCP patients with control volunteers using the software Praat. Acoustic analysis results of 18 unilateral VCP patients were compared with age and sex matched 72 normal adult volunteers. Comparison of acoustic analysis results of male and female VCP patients with their age and sex matched control groups revealed statistically significant difference in jitter, shimmer, and noise-to-harmonics ratio values (P < 0.01) in both groups. There were no differences in mean fundamental frequency and intensity values. We conclude that these differences were in accordance with the results obtained by commercially available voice analysis programs. This study reflects the first results obtained with Praat software in VCP patients. Using the software Praat, is free and easy, that supports the clinician to rely on objective scientific data.