Effectiveness of Semi-Occluded Vocal Tract Exercises (SOVTEs) in Patients with Dysphonia: A Systematic Review and Meta-Analysis
Journal of Voice
Pozzali, I., Pizzorni, N., et al. (2024).
Journal of Voice, 38(1), 245.e17-245.e35.
This systematic review and meta-analysis compares the effects of semi-occluded vocal tract exercises to the effects of other voice therapy interventions (e.g., other voice therapy exercises, vocal hygiene programs, surgery, pharmacological treatments, placebo, no intervention) in adults, 18 years and older, with dysfunctional or organic dysphonia.
No funding received
From database inception to December 2020
Randomized controlled trials (RCTs); non- or quasi-RCTs; quasi-experimental studies; pilot studies
8 studies included in the systematic review; 7 studies included in the meta-analysis
<div>Semi-occluded vocal tract exercises (SOVTEs) had the following effects for individuals with dysphonia when compared to control interventions:</div>
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<ul>
<li><strong>fundamental frequency:</strong> statistically improved effects (MD = -14.42);</li>
<li><strong>subglottic pressure: </strong>statistically improved effects (MD = -1.47);</li>
<li><strong>shimmer: </strong>significantly negative effects (MD = -0.43);</li>
<li><strong>self-assessment </strong>(per Voice Handicap Index/Voice Related Quality of Life): significantly negative effects (MD = -0.23) </li>
<li><strong>Vocal Tract Discomfort Scale: </strong>significantly negative effects (MD = -4.85).</li>
</ul>
<div>Control interventions demonstrated a non-significant favorable effect for jitter and overall grade of dysphonia. While SOVTEs demonstrate better significant results compared to control interventions for F0 and subglottic pressure measures, the authors conclude that overall the "results obtained show that voice therapy based on SOVTEs is not to be considered significantly superior if compared to other treatments" (p. 245.e31) for adults with dysphonia.</div>
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