title: Modeling the effects of a posterior glottal opening on vocal fold dynamics with implications for vocal hyperfunction.
abstract: Despite the frequent observation of a persistent opening in the posterior cartilaginous glottis in normal and pathological phonation, its influence on the self-sustained oscillations of the vocal folds is not well understood. The effects of a posterior gap on the vocal fold tissue dynamics and resulting acoustics were numerically investigated using a specially designed flow solver and a reduced-order model of human phonation. The inclusion of posterior gap areas of 0.03-0.1 cm(2) reduced the energy transfer from the fluid to the vocal folds by more than 42%-80% and the radiated sound pressure level by 6-14 dB, respectively. The model was used to simulate vocal hyperfucntion, i.e., patterns of vocal misuse/abuse associated with many of the most common voice disorders. In this first approximation, vocal hyperfunction was modeled by introducing a compensatory increase in lung air pressure to regain the vocal loudness level that was produced prior to introducing a large glottal gap. This resulted in a significant increase in maximum flow declination rate and amplitude of unsteady flow, thereby mimicking clinical studies. The amplitude of unsteady flow was found to be linearly correlated with collision forces, thus being an indicative measure of vocal hyperfunction.
authors.affiliation: Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Matías
authors.initials: M
authors.lastname: Zañartu
authors.affiliation: Department of Electronic Engineering, Universidad Técnica Federico Santa María, Valparaíso, Chile.
authors.forename: Gabriel E
authors.initials: GE
authors.lastname: Galindo
authors.affiliation: Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York 13699.
authors.forename: Byron D
authors.initials: BD
authors.lastname: Erath
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: Sean D
authors.initials: SD
authors.lastname: Peterson
authors.affiliation: Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907.
authors.forename: George R
authors.initials: GR
authors.lastname: Wodicka
authors.affiliation: Center for Laryngeal Surgery and Voice Rehabilitation, Massachusetts General Hospital, Boston, Massachusetts 02114.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Hillman
mesh_terms: D000399:Air Pressure; D003198:Computer Simulation; D005931:Glottis / Q000503:physiopathology*; D006801:Humans; D016014:Linear Models; D008962:Models, Theoretical; D010699:Phonation / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology; D013018:Sound Spectrography; D013061:Speech Acoustics; D013223:Statistics as Topic; D014827:Vocal Cords / Q000503:physiopathology*; D014832:Voice Disorders / Q000503:physiopathology*; D014833:Voice Quality / Q000502:physiology