Measuring Vocal Fatigability in Teachers: The Vocal Fatigability Scale for Teachers (VFS-T)

Objectives: This study focuses on the distinction between vocal fatigability and vocal fatigue (VF), highlighting the importance of vocal fatigability when assessing teachers' quality of life. Vocal fatigability is more critical for quality of life than performance or perceived VF because it considers the accumulation and chronicity of fatigue over isolated tasks. The objectives are to develop and validate the Vocal Fatigability Scale for Teachers (VFS-T), to assess teachers' levels of vocal fatigability, and to analyze variations based on personal and occupational traits. The VFS-T construct encompasses items related to vocal sensations and performance, their connection to accumulated demanding vocal activity, descriptions of recovery strategies, necessary rest periods, and the impact of VF on daily activities. Study design: A single cross-sectional study with an ex post facto design was conducted. Methods: The sample consisted of 184 active teachers with various vocal conditions. They completed the VFS-T questionnaire, provided personal and occupational data, and completed the VHI-10 questionnaire. The data collected were analyzed for item refinement, internal structure, reliability, validity, diagnostic capacity, cutoff values, and group differences. Results: The item refinement and internal structure analysis revealed a scale comprising 17 items grouped into two factors. The VFS-T shows good reliability and validity, with cutoffs at <15 for no fatigability, 15–27 for moderate fatigability, and >28 for high fatigability. Most teachers fall into the moderate fatigability range, with 72% experiencing vocal fatigability. Conclusions: The VFS-T is a reliable tool for detecting vocal fatigability in teachers. This scale focuses on the construct of vocal fatigability, which is related to chronicity of VF and limitations in daily activities in teachers.