Correlation of Multiple Measures of Voice Evaluation Among Individuals with Muscle Tension Dysphonia: An Exploratory Study

Primary Muscle Tension Dysphonia (MTD) occurs in the absence of structural or neurologic etiologies. Patients with MTD are frequently encountered in clinics and are evaluated using multiple measures of voice evaluation. Studies reporting on the correlation of multiple measures of voice evaluation among individuals with MTD are minimal, which led to this study. This single-group correlational study involved 48 participants diagnosed with primary MTD at a tertiary care institute. Multidimensional measures of voice (acoustic, aerodynamic, auditory-perceptual, and self-rating) were obtained from the participants. GRBAS scale, Acoustic Voice Quality Index, Acoustic Breathiness Index, Maximum Phonation Duration, S/Z ratio, Voice Handicap Index, and Vocal Fatigue Index were the variables considered. These measures were correlated using Spearman's correlation (rho) within and between different measures of voice evaluation. Several statistically significant (P < 0.05) correlations were found within and across different measures of voice evaluation. Moderate to very high correlations (rho between 0.48 and 0.87) were found between auditory-perceptual measures and multiparametric acoustic measures. Weak to moderate correlations (rho between 0.31 and 0.62) were observed between the VHI and its subsections, with GRBAS, AVQI, and ABI. No statistically significant correlations were observed between aerodynamic measures and other measures of voice evaluation. Results from this study suggest that compared to across measures, the correlation between different variables was stronger within each measure of voice evaluation. These findings highlight the need for a multidimensional voice evaluation in patients with MTD.