Quantification of the false vocal-folds effects on the intra-glottal pressures using large eddy simulation
Mihai Mihăescu, Sid M. Khosla, Gutmark J. Ephraim · Proceedings of meetings on acoustics · 2013
During the closing phase of the phonation cycle the true vocal-folds (TVF) have a convergent-divergent shape. The negative pressures generated by the flow through the glottal passage are producing closing forces acting on the TVFs. They can affect both vocal-fold vibration and voice production, since they can accelerate the closing phase. Large Eddy Simulation approach is used to investigate the intra-glottal forces generated solely by the flow during the closing phase. The influence of the gap between the false vocal-folds (FVFs) and the location of FVFs with respect to the TVFs are analyzed. Based on anatomical measurements, four different widths between the FVFs and two different distances between the true and false vocal-folds are investigated for the same trans-laryngeal pressure. The TVFs gap is kept constant. All cases exhibit a non-symmetric flow behavior in the mid-frontal plane. As the distance between the FVFs is decrease beyond a threshold value (still greater than glottal width), there is an increase in the magnitude of the closing forces acting on the TVFs. On the divergent slope of the glottis, these forces were found for some of the cases to be up to four times greater in magnitude as compared with the Baseline case.