The laryngeal channel as a variable venturi-meter

A model of the larynx, based on the analogy between the laryngeal channel and a constriction in a pipe, was developed by integrating the actual movements of the vocal cords during the quiet respiratory cycle. The model allows one to simulate and explain (1) the shape (tilted 8 with counterclockwise sign and cycle aperture) of the upper airway pressure-flow diagram, (2) the asymmetry between inspiratory and expiratory phases and (3) the variation of upper airway resistance with gas mixture.