Physical mechanisms of phonation onset: a linear stability analysis of an aeroelastic continuum model of phonation.
In an investigation of phonation onset, a linear stability analysis was performed on a two-dimensional, aeroelastic, continuum model of phonation. The model consisted of a vocal fold-shaped constriction situated in a rigid pipe coupled to a potential flow which separated at the superior edge of the vocal fold. The vocal fold constriction was modeled as a plane-strain linear elastic layer. The dominant eigenvalues and eigenmodes of the fluid-structure-interaction system were investigated as a function of glottal airflow. To investigate specific aerodynamic mechanisms of phonation onset, individual components of the glottal airflow (e.g., flow-induced stiffness, inertia, and damping) were systematically added to the driving force. The investigations suggested that flow-induced stiffness was the primary mechanism of phonation onset, involving the synchronization of two structural eigenmodes. Only under conditions of negligible structural damping and a restricted set of vocal fold geometries did flow-induced damping become the primary mechanism of phonation onset. However, for moderate to high structural damping and a more generalized set of vocal fold geometries, flow-induced stiffness remained the primary mechanism of phonation onset.
Zhang
Zhaoyan
Z
The Laryngeal Dynamics Laboratory, Division of Head and Neck Surgey, David Geffen School of Medicine at UCLA, 31-24 Rehabilitation Center, Los Angeles, California 90095-1794, USA. zyzhang@ucla.edu
Neubauer
Juergen
J
Berry
David A
DA
D001696:Biomechanical Phenomena; D004548:Elasticity; D004735:Energy Transfer; D005931:Glottis / Q000502:physiology; D006801:Humans; D016014:Linear Models; D008953:Models, Anatomic; D008962:Models, Theoretical; D010699:Phonation / Q000502:physiology*; D025341:Principal Component Analysis; D012123:Pulmonary Ventilation / Q000502:physiology*; D014732:Vibration; D014827:Vocal Cords / Q000502:physiology*