Measurements of viscoelastic properties of the false vocal fold

Much has been learned about the viscoelastic properties of the true vocal fold, including its linear and nonlinear viscoelastic properties under both tensile and shear deformation. Very little is known about the viscoelastic behavior of the false vocal fold, however. Clinical observations and computational modeling studies of phonation have suggested that the false fold could contribute to the aerodynamics and sound generation processes of human voice production, either with or without ventricular fold adduction and flow-induced oscillation. In order to better understand the potential role of the false fold in phonation, this paper reports some preliminary measurements on the nonlinear viscoelastic behavior of human false vocal fold tissues. Passive uniaxial stress-strain response of false fold tissue was measured by a muscle lever system as a function of both loading rate and static tensile strain level. A quadratic polynomial model was used to curvefit the empirical data and the elastic modulus (tangent Young’s modulus) of the tissue was calculated.