Phonation

Question 1

VF’s _____ via PCA muscles during inhalation :: VF’s ______ via LCA, IA, TA muscles

Answer 1

abduct :: adduct

Question 2

VF’s open bottom to top. T or F?

Answer 2

True; VF’s open at bottom first; then the opening proceeds to top of the VF’s. As top opens, bottom begins to close.

Question 3

The movement of the VF’s opening and closing creates a ___________.

Answer 3

vertical phase difference

Question 4

The MUCOSAL WAVE occurs as a result of?

Answer 4

The VF’s vibrating;

Question 5

Mucosal Wave

Answer 5

VF cover/mucosa appears to slide over the VF body –> slides during vibration & produces a wave in the mucosa.

Question 6

Where does the Mucosal Wave appear to travel?

Answer 6

Across the superior surface of the VF’s about 1/3 to 2/3’s of the way from the lateral edge of the fold.

Question 7

What can affect normal vibration or diminish wave?

Answer 7

Scarring or stiffening by disease or surgical procedure.

Question 8

When a gas/liquid flows through a constricted passage causing the velocity to increase while outward pressure of the gas molecules decreases is?

Answer 8

The Bernoilli Effect

Question 9

Re: The Bernoulli Effect

The pressure drop is ________ to the direction of the blow.

Answer 9

perpendicular

Question 10

Bernoilli Effect and the VF’s

Answer 10

1. subglottal pressure forces VF’s apart
2. narrow space created in glottis causes velocity of air molecules to increase
3. increase in air molecule velocity= decrease in pressure between VF’s
4. decrease in pressure causes walls of glottis to come together (+natural elastic recoil of VF’s)

Question 11

Myoelastic refers to ….

Answer 11

the laryngeal muscle activity that occurs during phonation and the effects of laryngeal muscle activity on the elasticity of VF’s.

Question 12

Aerodynamic refers to …

Answer 12

the aerodynamic determinants of the vibratory cycle (ie: opening & closing phases of vibration)

Question 13

What are the 2 aerodynamic foces that are determinants of VF vibration?

Answer 13

1. Subglottal Pressure (Ps)

2. Negative pressure due to Bernoulli effect

Question 14

What are the 3 main points of VT Inertance?

Answer 14

1. Sustained VF vibration is driven partly by transglottal pressure & supraglottic pressure
2. Ps increases, VFs open, glottal airflow increases from sluggish to rapid b/c pressure builds up between & above VF’s.
3. Glottis closes & forward momentum & acceleration of VT air column continues, Airflow through glottis can’t keep up & this creates suction, which further closes the glottis.

Question 15

The build up & release of supraglottic pressure is delayed in respect to opening & closing of VF’s creates?

Answer 15

Vocal Tract Inertance

Question 16

What 2 mechanisms control frequency?

Answer 16

1. the cover model

2. the body cover model

Question 17

The Body Cover Model

Answer 17

Activity of the TA muscle can either increase or decrease frequency depending on the depth of VF vibration & level of activity in the CT muscle.

Question 18

During normal to high intensity speech or singing in chest or head regiser, the _____ and _____ are in vibration.

Answer 18

VF body and VF cover

Question 19

What type of phonation results in increased amplitude & depth of vibration?

Answer 19

High intensity (loud) phonation

*(TA muscle is likely to be involved in vibration)

Question 20

What happens when the TA contracts during loud phonation?

Answer 20

The overall stiffness/tension of VFs will increase & frequency will increase.

(as long as CT muscle is not at its maximum)

Question 21

What happens when CT activity is at its maximum during loud phonation?

Answer 21

Frequency will decrease due to TA contraction. TA will shorten VFs & will decrease overall VF stiffness.

Question 22

Increased intensity = increased amplitude of vibration –> VF’s to lengthen & VF tension to increase –> increases frequency. This is also known as?

Answer 22

Dynamic Strain

Question 23

Non linear tissue movement

Answer 23

Convergent glottis: VFs open from bottom to top, transglottal pressure is positive, net tissue velocity is outward & air molecules converge.

Divergent glottis: Vfs close bottom to top, transglottal pressure is negative, net tissue velocity is inward & air molecules diverge.

*asymmetry in air pressure (+ for VF opening & – for VF closing) that is essential for self sustained vibration.

Question 24

What type of sound is generated by the VF’s?

Answer 24

It generates a quasi-periodic complex tone.

Question 25

What are the 3 things that control intensity?

Answer 25

1. Below the larynx- increased Ps
2. At the larynx- increased VF adduction
3. above the larynx- VT adjustments

Question 26

What is vocal quality determined by?

Answer 26

It is determined by the periodicity of VF vibration & degree of glottic closure