The long range aim of this project is the quantification and interpretation of irregular vocal fold vibration during self-oscillation, relevant for the prevention and treatment of voice disorders. This quantification of irregular oscillations will be accomplished with the aid of multiple-camera high-speed video imaging and excise larynx experiments. Utilizing information imaged from multiple views, 3D trajectories will be tracked for an array of fleshpoints along the superior and medial edges of coronal cross-sections of the folds. Steady-state, transient and irregular vocal fold oscillations will be imaged, and precise 3D reconstructions will be performed. Hypothesized mechanisms of vibrational instabilities will be tested with direct application for the prevention and treatment of voice disorders.
Specific aims i nclude: (1) using multiple-camera high-speed video imaging, quantify the 3D oscillations of the folds for a variety of periodic regimes (e.g., oscillations corresponding to chest-like, falsetto-like and fry-like phonations). Contrast the vibratory patterns of the regimes. (2) Quantify vocal fold oscillations during bifurcations (sudden qualitative changes in the vibratory pattern of the folds). Within the framework of nonlinear dynamics, evaluate current hypotheses regarding the physiological mechanisms of these transitions and instabilities. (3) Quantify the eigenmodes, eigenfrequencies, and damping ratios of the folds. To what extent are the phonation frequencies of aim 1 governed by eigenfrequencies? Can the phonatory regimes of aim 1 and the bifurcations of aim 2 be expressed as superpositions of just a few underlying eigenmodes? To what extent can the bifurcations of aim 2 be viewed as desynchronizations of underlying eigenmodes? (4) Evaluate several models of vocal vibration by comparing predicted fleshpoint trajectories with those observed experimentally. Augment the theoretical interpretibility of the data gathered in aims 1-3 by integrating the empirical observations into updated versions of the models. (5) By imposing the same restrictions on the excised larynx set-up as those encountered clinically (limited light, limited space for imaging equipment, imaging from a superior aspect only) adapt the above high-speed 3rd reconstruction techniques for clinical use.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29DC003072-04
Application #
6175392
Study Section
Sensory Disorders and Language Study Section (CMS)
Program Officer
Shekim, Lana O
Project Start
1997-05-01
Project End
2000-06-30
Budget Start
2000-05-01
Budget End
2000-06-30
Support Year
4
Fiscal Year
2000
Total Cost
$31,264
Indirect Cost
Name
University of Iowa
Department
Other Health Professions
Type
Schools of Arts and Sciences
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Berry, D A; Verdolini, K; Montequin, D W et al. (2001) A quantitative output-cost ratio in voice production. J Speech Lang Hear Res 44:29-37
Berry, D A; Montequin, D W; Tayama, N (2001) High-speed digital imaging of the medial surface of the vocal folds. J Acoust Soc Am 110:2539-47
Berry, D A; Clark, M J; Montequin, D W et al. (2001) Characterization of the medial surface of the vocal folds. Ann Otol Rhinol Laryngol 110:470-7
Alipour, F; Berry, D A; Titze, I R (2000) A finite-element model of vocal-fold vibration. J Acoust Soc Am 108:3003-12