Tissue mobilization during double source of vibration semioccluded vocal tract exercises: A neck and face surface acceleration study

Purpose: This study primarily aimed at observing the possible tissue mobilization on facial, neck, and chest tissues caused by different double source of vibration semioccluded vocal tract exercises (DSV-SOVTEs). Another goal was to inspect the degree of self-perceived sensation of a massage-like sensation. Method: Fifty-five participants engaged in a set of several DSV-SOVTEs: (a) phonation with a silicone tube submerged 2 and 8 cm below water surface, (b) Acapella Choice device, (c) lip trills, and (d) tongue trills. A self-perceived massage-like sensation was also assessed. All exercises were performed at three loudness levels. Tissue mobilization signal was captured by four accelerometers placed in four different body regions: (a) over the cheek, (b) over the neck, (c) over the thyroid cartilage, and (d) over the suprasternal notch. Results: There is a differential effect of all DSV-SOVTEs on tissue mobilization. All four observed dependent variables from tissue oscillation modulation (frequency, amplitude, jitter, and shimmer) showed significant three-way interactions. In general, amplitude and frequency of tissue oscillation modulation increases with loudness. A self-perceived massage-like sensation showed highly significant differences between DSV-SOVTEs. Conclusions: All DSV-SOVTEs do mobilize tissues. Type of exercise, loudness level, and body region produce an effect on all tissue oscillation variables. Acapella device produces the largest amplitude of vibration, lowest frequency, and more regular oscillation of tissue. Water resistance therapy showed the most irregular tissue oscillation. Control of these variables is likely to be relevant to obtain the best outcomes in patients.