Vibration parameter extraction from endoscopic image series of the vocal folds.
An approach is given to extract parameters affecting phonation based upon digital high-speed recordings of vocal fold vibrations and a biomechanical model. The main parameters which affect oscillation are vibrating masses, vocal fold tension, and subglottal air pressure. By combining digital high-speed observations with the two-mass-model by Ishizaka and Flanagan (1972) as modified by Steinecke and Herzel (1995), an inversion procedure has been developed which allows the identification and quantization of laryngeal asymmetries. The problem is regarded as an optimization procedure with a nonconvex objective function. For this kind of problem, the choice of appropriate initial values is important. This optimization procedure is based on spectral features of vocal fold movements. The applicability of the inversion procedure is first demonstrated in simulated vocal fold curves. Then, inversion results are presented for a healthy voice and a hoarse voice as a case of functional dysphonia caused by laryngeal asymmetry.
Döllinger
Michael
M
Department of Phoniatrics and Pediatric Audiology, University of Erlangen-Nürnberg, Erlangen, Germany. boert-rdm@gmx.de
Hoppe
Ulrich
U
Hettlich
Frank
F
Lohscheller
Jörg
J
Schuberth
Stefan
S
Eysholdt
Ulrich
U
D000328:Adult; D000465:Algorithms; D003198:Computer Simulation; D004548:Elasticity; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007828:Laryngoscopy / Q000379:methods*; D008954:Models, Biological; D010699:Phonation / Q000502:physiology*; D012016:Reference Values; D012680:Sensitivity and Specificity; D014732:Vibration; D014741:Video Recording; D014826:Vocal Cord Paralysis; D014827:Vocal Cords / Q000502:physiology / Q000503:physiopathology*; D014832:Voice Disorders / Q000503:physiopathology*