Erratum: Do Different Semi-Occluded Voice Exercises Affect Vocal Fold Adduction Differently in Subjects Diagnosed with Hyperfunctional Dysphonia?

Objective: To observe the possible differential effects of 8 different semi-occluded vocal tract exercises on glottal contact quotient (CQ) as a measure of vocal fold impact stress. Patients and Methods: Eighty participants were divided into two groups: an experimental group with hyperfunctional dysphonia and a control group of vocally healthy subjects. The participants were recorded before, during and after the exercises. Electroglottographic samples were analyzed to obtain CQ. Results: For the experimental group, all exercises, except lip trills and tongue trills, had an overall significant effect when conditions before, during and after the exercises were compared. The CQ presented differently across the 8 semi-occluded postures during exercise for both groups. For the experimental group, most exercises increased the CQ during practice. Only lip and tongue trills demonstrated lower CQ during exercise. Conclusions: Different semi-occluded exercises differentially affect vocal fold adduction. Lip and tongue trills produced the lowest CQ. Therefore, they may be recommended for decreasing glottal adduction. A straw submerged 10 cm below the water surface presented the greatest CQ. A shallower depth led to a lower CQ, while deeper submersion produced a higher CQ.