Abstract
This study examines the effectiveness of a voice training program designed for Islamic religious officials, who are occupational voice users with a significant vocal load. The participants included 34 healthy religious officials whose acoustic measures were within normal voice ranges for healthy adults (jitter < 1%; shimmer < 3%) and reported no voice complaints. Participants were randomly divided into two groups (experimental, n = 17; control, n = 17). The two-stage voice training program consisted of 32 sessions over 8 weeks with informative and voice exercise stages. Objective and subjective voice measurements were performed at the beginning and end of the research. Objective measurements included fundamental frequency, percentage of vocal pitch perturbation (jitter), percentage of vocal intensity perturbation (shimmer), and harmonics-to-noise ratio. Subjective voice measurements included the Singing Voice Handicap Index, Vocal Fatigue Index (VFI), and Voice-Related Quality of Life (V-RQoL) scores. All initial measurements other than VFI scores were within acceptable limits for both groups. There were no significant differences between the groups initially (p > 0.05) and no significant changes in the control group in the second evaluation (p > 0.05). However, there was significant improvement in the experimental group after the training program in all measures, including VFI scores (p < 0.05). This study shows the positive results of a voice training program. Voice training should be integrated into the formal education of occupational voice users or in-service training programs of relevant institutions.