A finite element simulation of vocal folds vibrations

A computer simulation for vibration of the vocal folds is presented. Free and forced oscillations were studied by imposing an impulse and time varying surface forces. The solution was obtained by a semidiscrete numerical method. A finite-element technique was used for solution of the problem in space and a Crank-Nicholson finite-difference method was used for time integration. Each vocal fold was divided into nine parallel layers of equal thickness where a two-dimensional finite method could be applied and layers were coupled to each other by a string law. Triangular elements of different size were selected such that finger elements appeared in the tip of the fold, where the largest and most probable movement was expected. Two different materials, corresponding to the muscle and cover, were considered in the model of vocal cords. Horizontal and vertical displacements of nodal points were obtained as a function of time. In addition, the response of the system to a sinusoidally varying force was obtained and compared with experimental results of an excised larynx of similar loading for validation of model