The Bernoulli Principle predicts that pressure within the glottis ___ as particle velocity of air molecules within the glottis increases. The __ theory of voice production incorporates this principle.

• A. increases; neurochronaxic
• B. decreases; neurochronaxic
• C. decreases; myoelastic-aerodynamic
• D. increases; myoelastic-aerodynamic

Answer: (C)

The main idea is that, in a constricted flow like the glottis, increasing air velocity causes a drop in pressure. As air speeds up through the narrow opening created by the vocal folds, the pressure at that spot falls, which helps pull the folds back together and drive the rapid opening–closing cycle that sustains vibration. The theory that specifically incorporates this aerodynamic interaction with tissue elasticity is the myoelastic-aerodynamic theory of voice production. Neurochronaxic theory, in contrast, centers on neural timing and doesn’t explain how the pressure-velocity relationship in the glottis contributes to vibration. So the correct combination is that pressure decreases as velocity increases, and the myoelastic-aerodynamic theory explains this mechanism.