Improved definitions of voice efficiency

Novel measures of voice efficiency are presented. Separate measures which distinguish acoustic production and transmission are defined. The analysis uses the integral equation for fluid mechanical energy, applied to a control volume encompassing the human airway system and its component parts. The physiological work inputs and acoustic work outputs are identified, along with the interplay of these with the work performed by other mechanisms present in the vocal system, such a viscous dissipation and work done by the airflow on the vocal folds. Non-linear interaction between acoustic production and transmission is also explicitly accounted for by this analysis. Reduced-order modeling of human phonation is presented to provide a comparison with previous definitions of voice efficiency.