An Experimental Investigation of the Quasi-Steady Assumption in Speech

Human speech is initiated when the lungs achieve a critical pressure forcing the vocal folds apart, expelling air through the glottis, and beginning self-sustained oscillations. The oscillations arise due to coupling between the aerodynamic forces and the structural properties of the vocal folds. During each phonation cycle the glottis transitions from a convergent channel upon opening, to a uniform, and finally a divergent channel before closing and repeating the cycle. The resulting pulsatile flow field which emanates from the vocal folds forms the raw component of speech.