Relationships Between Aerodynamics and Voice Symptoms in Primary Muscle Tension Dysphonia

Measures of self-perceived voice symptoms and aerodynamic assessments are commonly used in voice clinics, particularly for patients with primary muscle tension dysphonia (pMTD). However, relationships between these perceptual metrics and physiological parameters are not well-understood, making it difficult to determine how one informs the other in clinical decision-making. The goal of this study was to characterize relationships between self-perceived voice symptoms and physiological aerodynamic parameters in individuals with and without pMTD.

Aerodynamic voicing efficiency metrics (mean peak subglottal pressure, mean transglottal airflow, peak expiratory airflow, expiratory airflow duration, and total expiratory volume) and self-perceived voice symptoms (vocal effort, vocal fatigue, vocal tract discomfort, and vocal impact) were collected in 45 participants with (n = 20) and without (n = 25) pMTD. Group differences in aerodynamic parameters and voice symptom metrics were determined with t tests. Relationships between these measures were determined by Pearson's correlations and Principal Component Analysis.

Although patients with pMTD had significantly higher vocal effort, vocal fatigue, and vocal tract discomfort scores compared with vocally healthy controls (P's < 0.0001), there were no significant group differences in any of the aerodynamic parameters after Bonferroni correction (P's > 0.005) and no significant correlations between voice symptoms and aerodynamics (P's > 0.05). The voice symptom metrics clustered closely together and accounted for the majority of the variance in the pMTD cohort, while subglottal pressure and transglottal airflow aerodynamic parameters contributed to a lesser extent.

The weak relationships between voice symptoms and aerodynamics in patients with pMTD suggest that somatosensory perceptions of voice symptoms do not always correspond to underlying aberrant laryngeal-respiratory motor patterns. Additionally, non-significant trends toward increased and more variable subglottal pressures and transglottal airflows in the pMTD group could indicate the presence of pMTD phenotypes.