Objectives: The objective of this study was to explore the effectiveness of a 3-week training program with the voice therapy "Lax Vox" for teachers.
Methods: Four healthy female teachers participated as volunteers for the study. Several voice measurements of perception, acoustics, aerodynamics, and self-evaluation were investigated. Furthermore, a survey to rate the applicability of Lax Vox was also part of the study. To assess the treatment effects of the Lax Vox training, an effect size analysis (dunb) was conducted.
Results: After 3 weeks of training, medium and large improvements were found in some parameters of perceptual and acoustic voice quality assessments (dunb >0.50 and dunb >0.80, respectively). Furthermore, medium improvements were revealed in some parameters of self-evaluation (ie, physical and total scale of the Voice Handicap Index) and aerodynamic (ie, maximum phonation time) assessments (all dunb >0.50). Additionally, acoustic measures of vocal function showed an expansion in the upper contour of voice range profiles after training. Particularly, the main improvements in the voice range profile was found in the modal and the beginning of the falsetto voice registers. There was an increase of the intensity levels of about 4.6 dB. No changes were revealed in some acoustic measures of the voice range profile, self-evaluation measurements, and the perception of breathy voice quality (all dunb <0.20). Finally, the applicability of Lax Vox perceptually showed clear support in training success, learning process, and transfer to the daily routine.
Conclusions: Lax Vox training for teachers appears to improve select measures of voice quality, maximum phonation time, vocal function, self-evaluation, and perceived applicability.
Keywords: dysphonia; lax vox; preventive voice training; teacher; voice therapy.
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