Parameterization of Articulatory Movements Based on Cascaded First-order Systems and its Application

By applying tension asymmetries in a finite-element model of vocal fold vibration, a variety of modes of phonation were simulated. The biophysical model incorporated tissue mechanics, glottal aerodynamics, and acoustics of the vocal tract. For simplicity and speed, glottal aerodynamics were modeled with a modified Bernoulli equation. Vocal tract acoustics were modeled using a wave reflection and transmission-line approach. An increase in tension in one fold generally increased the oscillation frequency of both folds, which can be explained by the mechanism of eigenmode entrainment, a common phenomenon in nonlinear oscillators. However, the vocal fold with the higher tension had a higher mucosal wave velocity and a smaller amplitude of vibration.