For understanding the phonatory process in human voice production, physical as well as numerical models have been suggested. Material properties within these models are crucial for achieving vocal fold dynamics being close to in vivo human laryngeal dynamics. Hence, different approaches have been suggested to gain insight into human laryngeal tissue, evaluate clinical treatment, as well as to analyze and verify parameters within synthetically built vocal folds.
Purpose of Review: The authors want to give an overview of approaches on receiving material parameters being important in voice research. For the different devices and methods being applied for different set-ups, we will present the functionality and applicability. Hence, for future work, this review shall give an indication, what kind of measurement techniques are suitable for the intended study, advantages or disadvantages of the approaches, and what parameters can be obtained from them.
Recent Findings: For in vivo experiments, Color Doppler Imaging was found to be suitable for receiving vocal fold stiffness properties. Applying rheological measurements, the elastic modulus and the dynamic viscosity can be determined. In combination with histological analysis it is possible to objectively evaluate clinical treatment. Optical Coherence Tomography enabled to detect tissue boundaries for in vitro vocal folds. A pipette aspiration setup allowed to identifying spacially resolved mechanical properties of synthetic vocal folds. Numerical biomechanical models like finite element models have shown to be suitable to identify isotropic elastic material parameters
Keywords: Vocal folds, rheometer, viscosity, material parameters, Mucosal Wave Visualization, Histology, Rheology, Augmentation, Gas Bearing Electrodynamometer, Laser Triangulation