Imaging of auto-oscillating vocal folds replicas with left–right level difference due to angular asymmetry

Vertical level difference due to vertical angular asymmetry (up 20°) between the normal (right) and tilted (left) vocal fold (VF) is experimentally assessed in framework of unilateral paralysis. The upstream pressure high-speed vibration imaging for different camera view angles are during steady-state auto-oscillation three mechanical VF replicas. A global image-based correlation allows assess oscillation frequency independently from angle. Resulting frequencies matches ones obtained aerodynamic data. Mean cycles videokymographic line-scans at positions along posterior–anterior direction analysed. Left–right displacement phase difference, axis shift left–right mucosal wave identified as essential parameters quantifying asymmetry. influence degree asymmetry, scan position replica discussed.