-The different stiffness characteristics of the vocal fold layers result in mechanically de-coupled grouping of layers to form the mucosa cover (epithelium and SLP), Vocal ligament (ILP and DLP), and the body of the vocal folds involving the vocalis muscle
Pulse
-By Van den berg
-most widely accepted model of voice production. This model describes voice production as an interaction of muscle force (myo), tissue elasticity (elastic), and air pressures and flows (aerodynamic).
V = k/P or VP = k (p = pressure and v = volume)
Bernoulli principle
a gas such as air passing through a narrow channel (adducting vocal folds; constriction of the glottis) increases in velocity and decreases in pressure.
The negative pressure between the folds further helps to close them completely pulling them towards each other.
One cycle of phonation requires 4 phases of VF movement: opening, open, closing, and closed. Vibration will continue during phonation as long as there is medial compression with the alternating of positive and negative pressures. Because no external force has to be applied for each cycle, the VFs are considered to be a self-sustaining oscillator. The VFs will vibrate for as long as an individual is producing a voiced sound. For voiceless sound or to inhale, the glottis is opened by the PCA.
What is the tongue primarily made up of?
Extrinsic Tongue muscles:
Intrinsic Tongue Muscles:
90% of FRONT consonants are produced with verticalis, transverse and genioglossus
The Source Filter Theory
describes the modification of the sound produced at the larynx as it travels through the vocal tract and out the lips on three graphs: the source function, transfer function, and output function.
Tells us the maturational status of neurological and physiological systems
Reflects prematurity in higher F0 and in more stressful cries
Apnea of infancy reflected in lower F0