Investigation of the immediate effect of semi occluded vocal tract exercises in adults with unilateral vocal fold paralysis

The current research aims to show the immediate effect of humming, straw phonation and straw phonation into water exercises implemented for 1, 3, 5 and 7 minutes in steady phonation or pitch glides. The experiment and control groups consist of 40 participants, 20 of whom are in each group. The variables of F0, sound pressure level, jitter, shimmer, noise-harmonics ratio, acoustic voice quality index, cepstral peak prominence-smoothed, vocal effort and perceived improvement were used to measure the immediate effect of exercises. As a result of the analyses of variance, it was found that jitter, shimmer and vocal effort decreased and the voice was perceived better from the 3rd minute in the humming exercise in steady phonation. For the straw phonation into water, the lowest shimmer value was found at the 3rd minute and the voice was perceived better, and after the 3rd minute, these values started to deteriorate. For the straw exercise, vocal effort decreased from the 1st minute. In all exercises, F0 and sound pressure level increased, and vocal effort decreased. It was found that the increase in F0 and sound pressure level was higher and vocal effort was lower in the glide exercises compared to steady phonation. As a result of this study, it was concluded that therapy and home exercise planning should be done by paying attention to the exercise type, form and duration factors in order to get the best results in individuals with unilateral vocal fold paralysis.