Effect of Vocal Function Exercises on the Voice Handicap Index, Vocal Fatigue Index, and Number of Vocal Fatigue Symptoms in Bank Workers: Single-Blinded Randomized Controlled Trial

Vocal fatigue (VF) is a significant portion of occupational voice disorders. Researchers have proposed numerous therapeutic approaches to alleviate VF. However, the efficacy of vocal function exercises (VFEs) as a safe, effective, and simple method is unclear. The current study aims to investigate the effect of VFEs on occupational-related VF in Iranian bank workers. A single-blinded randomized controlled trial with four-level blocking After screening 444 workers, 43 persons with vocal fatigue (VF) were allocated between intervention and control groups. The gender of participants was considered a confounding parameter. Intervention group participants (IGP) (20 males and two females) practiced vocal function exercises (VFEs) (online training) for two weeks, while control group participants (CGP) (20 males and a female) continued their routine lifestyle. The Number of Vocal Fatigue Symptoms (NoVFS), Maximum Phonation Time (MPT), Voice Handicap Index (VHI), and Vocal Fatigue Index (VFI) at pre-intervention and post-intervention levels were gathered and compared. According to the intergroup, pre-/post-intervention differences, and intragroup analysis, the IGP experienced a significant reduction in the NoVFS ( P = 0.006, P = 0.009), the mean score VHI (P:0.006, P: 0.001, P: 0.001), the total mean score of VFI ( P