VOICE DISORDERS IN PROFESSIONAL VOICE USERS: IDENTIFYING EARLY SIGNS AND OCCUPATIONAL RISK FACTORS

Abstract

This study evaluated early vocal changes and occupational risk factors in 150 professional voice users (50 teachers, 40 call-centre operators, 30 singers, 30 actors) using mixed quantitative and qualitative methods. Acoustic measures revealed that call-centre operators exhibited the highest mean jitter (1.2 ± 0.3 %) and shimmer (5.8 ± 1.2 %) and the lowest harmonic-to-noise ratio (HNR; 16.5 ± 3.1 dB), whereas singers showed the most favorable vocal profiles (jitter = 0.6 ± 0.1 %; shimmer = 3.9 ± 0.8 %; HNR = 20.3 ± 1.9 dB). Occupational exposure metrics peaked in call-centre operators (mean daily voice use = 7.2 ± 1.0 hours; background noise = 75 ± 6 dB) and were lowest among singers (5.8 ± 1.5 hours; 60 ± 4 dB). Hydration adherence ranged from 50 % (call-centre) to 80 % (singers), and regular rest‐break compliance varied from 35 % to 70 %. Pearson correlations linked increased shimmer with noise level (r = .53, p < .01) and elevated jitter with voice-use duration (r = .42, p < .05), while HNR inversely correlated with jitter (r = –.58, p < .01). A hierarchical regression model (R² = 0.45, F(7,142) = 16.5, p < .001) identified excessive phonatory load, dehydration, and insufficient rest as significant predictors of subclinical dysphonia, which affected 55 % of call-centre operators, 40 % of teachers, 35 % of actors, and 30 % of singers. Qualitative interviews underscored delayed symptom reporting due to normalization of vocal fatigue. These findings support implementing routine acoustic monitoring and targeted preventive strategies (voice rest scheduling, hydration protocols, environmental controls) to detect and mitigate early voice disorders in high-risk occupational groups.