  The coupling of vocal fold (source) and vocal tract (filter) is one of the
most critical factors in source-filter articulation theory. The traditional
linear source-filter theory has been challenged by current research which
clearly shows the impact of acoustic loading on the dynamic behavior of the
vocal fold vibration as well as the variations in the glottal flow pulses
shape. This paper outlines the underlying mechanism of source-filter
interactions; demonstrates the design and working principles of coupling for
the various existing vocal cord and vocal tract biomechanical models. For our
study, we have considered self-oscillating lumped-element models of the
acoustic source and computational models of the vocal tract as articulators. To
understand the limitations of source-filter interactions which are associated
with each of those models, we compare them concerning their mechanical design,
acoustic and physiological characteristics and aerodynamic simulation.
