Evaluating the accuracy of one-dimensional glottal flow model in predicting voice production: comparison to experiments and three-dimensional flow simulations.

The glottal flow is often simplified as one-dimensional (1D) in phonation models to reduce computational cost. Although previous studies showed that a 1D flow model can predict voice production by a three-dimensional (3D) flow combined with a simplified two-mass vocal fold model, its validity in voice production involving more realistic 3D vibrations remains unclear. The goal of this study is to investigate the accuracy of the 1D flow model in predicting vocal fold vibration and voice production in a vocal fold model exhibiting a more realistic 3D vibration pattern, by comparing its prediction to that from a mechanical experiment and a 3D Navier-Stokes compressible flow model. The results showed that the 1D flow model predicted overall vibratory pattern similar to that observed in experiment and simulations based on the 3D flow model. However, the 1D flow model predicted slightly larger displacements and greater glottal flow fluctuations than the 3D flow model. The 3D flow model revealed strong variations in surface pressure along the anterior-posterior direction, particularly during the closing phase, which was not captured by the 1D flow model. Despite these differences, the 1D flow model adequately reproduced major aerodynamic and vibratory features under typical normal phonatory conditions, supporting its use in phonation models for efficient voice simulations.