Quantification of loudness instability in tone production in embouchure dystonia

Embouchure dystonia (ED) is a task-specific disorder of voluntary fine motor control that has a severe impact on musicians' ability to perform. One critical skill for professional musicians is the ability to produce sustained notes with an even loudness, however this ability in ED has not been well defined. The present study therefore examined the time-varying dynamics of loudness in ED compared to healthy musicians, as well as its relationship to F0 variability, applying sound analysis of sustained notes. The findings revealed a significantly greater varia-bility with respect to both loudness and F0 among ED patients. Furthermore, loudness and F0 variability were strongly correlated, suggesting a shared pathological basis. We conclude that F0 variability and loudness instability are reliable measures for objectively characterising ED and assisting accurate diagnosis. The incorporating of quantitative acoustic tools into future diagnostic and therapeutic frameworks has the potential to enhance the objectivity and repro-ducibility of ED assessment.