Investigating the Effect of Semi-Occluded Vocal Tract Training With a Free-End Tube on Acoustic Characteristics and Glottal Performance in Dysphonic Adults: A Systematic Review
Journal of Voice
Asadollahpour, F., Baghban, K., et al. (2025).
Journal of Voice, Advance online publication. https://doi.org/10.1016/j.jvoice.2025.01.010.
<div>This systematic review explores the impact of semi-occluded vocal tract (SOVT) training with a free-end tube (i.e., straw) on acoustic and glottal outcomes in adults with dysphonia. </div>
Hamadan University of Medical Sciences (Iran)
January 1991 to September 2024
<div>Clinical trials</div>
3
<div>Results suggest that SOVT training with straws may improve glottal performance and acoustic characteristics in adults with dysphonia. One study reported reduced glottal contact quotients both during and after SOVT exercises, suggesting increased vocal efficiency. Two studies reported mixed results for acoustic measures, with one demonstrating positive outcomes, and the other reporting no significant difference. </div>
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<div>Limitations to this review include an overall lack of research, heterogeneity between studies, and a high risk of bias for each of the included studies. Additional, high quality research is needed to determine the true impact of SOVT training for dysphonic adults. </div>
