Based on the H-C two-mass vocal cord model, the common vocal pathology model, single and double vocal cord polyp model are deduced.The vibration equation of the vocal cord is analyzed from the angle of displacement and the glottal volume velocity.The effects of the polyp size on the vibration displacement and the glottal pressure and the glottal volume velocity are obtained by using the maximum bifurcation diagram. The simulation results show that larger polyp size can induce more serious the impact on the speaker sound. Combined with clinical diagnosis, the effectiveness of model is proved for the analysis of vocal cord polyp pathology.

vocal cord polyp model; vibration equation; bifurcation diagram; polyp size