Immediate effects of a semi-occluded water-resistance ventilation mask on vocal outcomes in women with dysphonia

Introduction

Semi-occluded vocal tract exercises (SOVTEs) are frequently used exercises in voice therapy. An important shortcoming to most SOVTEs is the inability to include continuous speech in these exercises. A variation of water-resistance therapy (WRT), during which a patient phonates through a resonance tube ending in water, was developed to include continuous speech: the semi-occluded water resistance ventilation mask (SOVM-WR). The current study investigated the immediate effects of this innovative technique on vocal outcomes of women with dysphonia.

Methods

A pretest-posttest randomized controlled trial was performed. Twenty female participants were randomly assigned to the experimental SOVM-WR group or the WRT (control) group. A blinded multidimensional voice assessment was conducted before and after a 30-minute therapy session with the assigned technique.

Results

No significant changes were found in acoustic or auditory-perceptual vocal outcomes in either of the groups, except for a significant increase in lowest frequency in both groups. Patient-reported outcomes (PROMs) showed significant improvements of vocal comfort, vocal effort, and voice quality in both groups, and participants indicated that they would use the techniques at home.

Conclusions

The similar results of the SOVM-WR to WRT and promising PROMs confirm its suitability as an alternative to the latter technique. Potential reasons for a lack of improvement of objective and auditory-perceptual vocal outcomes are vocal fatigue, tube dimensions and immersion, and the small sample size. Large-scale and longitudinal research is needed to examine whether the SOVM-WR has a higher transfer to spontaneous speech than WRT after a full therapy program.