Anterior-posterior characterization of intraglottal flow fields in excised canine larynges

Abstract

It has been espoused that intraglottal flow separation vortices (FSVs) play a critical role in the rapid closure of the vocal fold vibrations by acting as an additional pulling force that affects the maximum flow declination rate (MFDR). Clinically, MFDR is important because studies showed it highly correlates with loudness, intelligibility, and vocal efficiency. Previous studies that aimed to characterize the influence of FSVs were focused on their role in the mid-coronal plane. In the current study, particle imaging velocimetry was used to measure the intraglottal flow, specifically the FSVs, in the anterior–posterior aspects of the glottis during the closing phase of the vocal fold vibrations. The results show that the FSVs are extending along the length of the vocal fold in the anterior–posterior direction and that there is a direct relation between the size of FSVs and the magnitudes of the glottal divergence angles. The results also show that the centroid of FSVs occurs towards the anterior direction, where larger divergence angles are observed. These findings suggest that the FSVs in the anterior aspect have a more significant effect on the aerodynamic force acting on the glottal wall than the FSVs in the posterior aspect.