Validation and Evaluation of the Effects of Semi-Occluded Face Mask Straw Phonation Therapy Methods on Aerodynamic Parameters in Comparison to Traditional Methods

SummaryObjectives/HypothesisTraditional semi-occluded vocal tract therapies have the benefit of improving vocal economy but, do not allow for connected speech during rehabilitation. In this study, we introduce a semi-occluded face mask (SOFM) as an improvement upon current methods. This novel technique allows for normal speech production, and will make the transition to everyday speech more natural. We hypothesize that use of an SOFM will lead to the same gains in vocal economy seen in traditional methods.Study DesignRepeated measures excised canine larynx bench experiment with each larynx subject to controls and a randomized series of experimental conditions.MethodsAerodynamic data were collected for 30 excised canine larynges. The larynges were subjected to conditions including a control, two tube extensions (15 and 30 cm), and two tube diameters (6.5 and 17 mm) both with and without the SOFM. Results were compared between groups and between conditions within each group.ResultsNo significant differences were found between the phonation threshold pressure and phonation threshold flow measurements obtained with or without the SOFM throughout all extension and constriction levels. Significant differences in phonation threshold pressure and phonation threshold flow were observed when varying the tube diameter while the same comparison for varying the tube length at least trended toward significance.ConclusionsThis study suggests that a SOFM can be used to elicit the same gains in vocal economy as what has been seen with traditional semi-occluded vocal tract methods. Future studies should test this novel technique in human subjects to validate its use in a clinical setting.