Myoelastic-Aerodynamic Theory of Phonation

Bernoulli principle

According to this principle, a gas such as air passing through a narrow channel increases in velocity and decreased in pressure. The negative pressure between the folds further helps to close them completely by pulling them towards one another.

positive

As the glottis opens due to __________ pressure, the air flowing through the glottis meets the mass of air directly above it, creating compression of the air and increased positive air pressure.

3

Note that for phonation to occur the vocal folds do not have to be completely closed but cannot be father apart than around ____mm.

Bernoulli

Once the folds have been forced apart, they begin to recoil back to the midline due to their *natural elasticity.* As they begin to close, they form a narrow channel. *Second,* the air passing through this construction formed by the closing glottis becomes *negative* in pressure due to the effect of the _________________ principle

natural elasticity

Once the folds have been forced apart, they begin to recoil back to the midline due to their ___________ ____________.

negative

Pressures within the vocal tract immediately above the glottis (supraglottal pressures) also facilitate opening and closing of the glottis during vibration. The air that has already passed through the glottis travels up the *vocal tract.* The distance between the traveling body of air and the glottis increases, resulting in a ___________ pressure directly on the glottis.

vocal tract

The air that has already passed through the glottis travels up the

medial compression

To initiate vocal fold vibration, the vocal folds must adduct to close the glottis. This is achieved by the later cricoarytenoid and interarytenoid muscles, which exert force called...

increase

When the glottis is closed by medial compression the pressure of the air beneath the folds (sub glottal pressure) begins to _________.

apart

When the sub glottal pressure is strong enough, it overcomes the resistance of the closed glottis and forces the vocal folds ________.

self-sustaining oscillator

because vibration continues due to differences in transglottal pressures without an external force needing to be applied for each cycle, the vocal folds are considered to be

vibration

continues for as long as medial compression continues to be exerted, and the interaction between positive and negative air pressures maintains the alternating opening and closing go the glottis.

myoelastic-aerodynamic theory of phonation

describes voice production as an interaction of muscle force (myo), tissue elasticity (elastic), and air pressures and flows (aerodynamics)

PCA

for a voiceless sound or to inhale, the glottis is opened by the _______.

supraglottal positive air pressure

further raises the air pressure within the glottis, creating a stronger opening force.

supraglottal negative pressure

reinforces the negative pressure within the glottis, which facilitates a greater closing force.

duty cycle

the cycle of vibration can be though of as consisting of four phases of vocal fold movement: opening, open, closing, closed.