Comparison of one-dimensional and three-dimensional glottal flow models in left-right asymmetric vocal fold conditions

• Published in: The Journal of the Acoustical Society of America Vol. 151; no. 4; p. A133
• Main Authors: Yoshinaga, Tsukasa, Zhang, Zhaoyan, Iida, Akiyoshi
• Format: Journal Article
• Language: English
• Published: 01-04-2022
• ISSN: 0001-4966; 1520-8524
• DOI: 10.1121/10.0010890

While the glottal flow is often simplified as one-dimensional (1D) in computational models of phonation to reduce computational costs, the 1D flow model has not been validated in left-right asymmetric vocal fold conditions, as often occur in both normal and pathological voice production. It is unclear to what extent the 1D model approximates the effect of three-dimensional (3D) flow phenomena and fluid-structure interaction. In this study, we performed 1D and 3D flow simulations coupled with the two-mass vocal fold model and compared vocal fold vibration patterns at different degrees of left-right stiffness asymmetry. The flow and acoustic fields in 3D were predicted by solving the compressible Navier-Stokes equations using the volume penalization method and considering the moving vocal fold wall as an immersed boundary. The results showed that vocal fold vibration amplitudes and left-right phase differences in the 3D flow were predicted by the 1D flow model under conditions of small left-right asymmetry, while vocal fold vibration amplitudes were underestimated at conditions of large left-right asymmetry. This indicates that 1D flow models may be sufficient in modeling phonation under left-right asymmetric conditions, although the performance can be further improved by more accurately predicting air pressure on vocal fold surface.