The long-range objectives of this research are: (1) to develop a comprehensive theory of airflow in the larynx that will predict the pressure and velocity distributions and give an estimate of the aerodynamic forces inside the glottis; this will be useful not only in improving our understanding of phonation, but also as a direct application to computer simulation of speech production, (2) to investigate the effects of biomechanical properties of laryngeal tissues on fluid dynamics (the boundary effects); this will further our understanding of voice disorders caused by mechanical stresses and may be useful in future design and implementation of an artificial larynx. It is expected that a newly-developed computation technique will result in an accurate prediction of the velocity profile and aerodynamic forces in the glottis. Ultimately, the results of this investigation will be useful in the understanding the mechanisms of pitch, loudness, and quality control, and of the self-oscillation characteristics of the vocal folds. The study is both experimental and theoretical in nature. The first phase considers steady flow in the larynx. Experiments will be conducted to measure the air velocity and pressure in various plexiglass models of the larynx, and in canine excised larynges. Also, a numerical model will be developed to solve the equations of motion through laryngeal airways. Experimental data of phase one and data from biomechanical studies of laryngeal tissue will be used to validate the theoretical model. Phase two will consider pulsatile flow, with and without tissue movements. Experiments will be conducted to measure the time dependence of velocity and pressure in the excised larynx and the plexiglass models. The theoretical model will be extended to predict the unsteady velocity and pressure distribution.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
1R01DC000831-01A2
Application #
3217542
Study Section
Sensory Disorders and Language Study Section (CMS)
Project Start
1992-01-01
Project End
1995-12-31
Budget Start
1992-01-01
Budget End
1992-12-31
Support Year
1
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Arts and Sciences
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Alipour, F; Scherer, R C; Finnegan, E (1997) Pressure-flow relationships during phonation as a function of adduction. J Voice 11:187-94
Scherer, R C; Alipour, F; Finnegan, E et al. (1997) The membranous contact quotient: a new phonatory measure of glottal competence. J Voice 11:277-84
Alipour, F; Scherer, R; Knowles, J (1996) Velocity distributions in glottal models. J Voice 10:50-8
Alipour, F; Scherer, R C (1995) Pulsatile airflow during phonation: an excised larynx model. J Acoust Soc Am 97:1241-8