Predictions of Fundamental Frequency Changes During Phonation Based on a Biomechanical Model of the Vocal Fold Lamina Propria

Abstract

This study examines the local and global changes of fundamental frequency (F 0 ) during phonation and proposes a biomechanical model of predictions of F 0 contours based on the mechanics of vibration of vocal fold lamina propria. The biomechanical model integrates the constitutive description of the tissue mechanical response with a structural model of beam vibration. The constitutive model accounts for the nonlinear and time dependent response of the vocal fold cover and the vocal ligament. The structural model of the vocal fold lamina propria is based on a composite beam model with axial stress. Results show that local fluctuations such as F 0 overshoots and undershoots can be characterized by the biomechanical model and might be related to the processes of stress relaxation of vocal fold tissues during length changes. The global changes of F 0 declination in declarative sentence production can also be characterized by the model. Such F 0 declination is partially attributed to the peak stress decay associated with stress relaxation of the vocal fold lamina propria and partially to neuromuscular control of the vocal fold length.

The Relationship Between Tongue Trill Performance Duration and Vocal Changes in Dysphonic Women

“…14 The F 0 increased significantly from m3 in the EG, which is directly associated with the increase of the subglottic pressure and increase of the muscular tension. [15][16][17][18] The F 0 raise is compatible to the elevation in pitch identified in the acoustic perceptual analysis in this same moment.…”

Spatially varying properties of the vocal ligament contribute to its eigenfrequency response

“…The vocal fold cover and the vocal ligament may both be considered as the vibrating tissue components in the airflow-driven vibration of the vocal folds. In a basic beam model of vibration, the fundamental frequency of the vocal folds in an unstretched state is given as (Zhang et al, 2009) $$F_0=\frac{\alpha }{L^2}\sqrt{\frac{E{\kappa }^2}{\rho }}$$ where F 0 is the natural frequency of the lowest mode (under no applied tension), E is the elastic modulus, κ is the radius of gyration for the tissue cross-section, L is the length, ρ is the density of the tissue, and α is a constant equal of the order of unity. In the past, we have considered changes to the fundamental frequency as stretching of the vocal fold occurs (Zhang et al 2007).…”

“…1 that the cross-section of the vocal ligament is not constant, but includes tapering at the macula flavae. Past models for the predictions of fundamental frequencies have assumed the vocal fold cross-section to be constant (Zhang et al 2009, Zhang et al 2007). How spatial variations in the cross-sectional geometry could influence the fundamental frequency and vibration characteristics is unknown.…”

Elasticity and stress relaxation of rhesus monkey (Macaca mulatta) vocal folds

“…At strains larger than 20-30%, the stress response is highly nonlinear and demonstrates quantitative differences between individuals, sexes, as well as species (Haji, 1990;Min et al, 1995;Chan et al, 2007;Zhang et al, 2009;Riede et al, 2010). When vocal folds are strained, some stress is released ) and would cause a drop in f 0 if not compensated, for example, by further stretching.…”