AbstractHuman phonation is simulated, using a multiple- mass-spring model for the vocal cords and a transmission line model for the vocal tract, Attempts were made to simulate the effects pathologies have on the speech wave and the vibratory characteristics of the vocal fold tissue. Results indicate that changes 10 the mass and stiffness of the system can cause a regular (subharmonic) component to appear with the fundamental oscillation. Irregular unsteady oscillation also occurs under certain conditions.