05 - Phonation I

Question 1

Which is the correct term: vocal folds or vocal cords?

Answer 1

Vocal folds, although they may also be called “true vocal folds” or “vocal cords”

Question 2

What are the vocal folds?

Answer 2

A valve in the airway at the level of the larynx

Question 3

What are the vocal folds composed of (3)?

Answer 3

Epithelial tissue, mucus membrane, and muscle tissue

Question 4

What is the primary role of the vocal folds in speech?

Answer 4

To vibrate and thus generate the voice signal

Question 5

Name 2 non-speech functions of the vocal folds

Answer 5

Protecting the airway (closing during swallowing, coughing)

Assisting in strenuous lifting or pushing

Question 6

What other 2 structures, beside the vocal folds, play a role in protecting the airway during swallowing?

Answer 6

False vocal folds

Epiglottis

Question 7

True or False: when the muscles of the larynx bring the vocal folds very close together and air from the trachea/lungs is pushed through, the vocal folds will begin to vibrate

Answer 7

True

Question 8

What is the vibration of the vocal folds a result of?

Answer 8

Air being pushed through as the vocal folds continuously alternate between coming together (closing) and pushing apart (opening)

Question 9

What is another word for the vibration pattern of the vocal folds that produces sound?

Answer 9

Phonation

Question 10

How is the diverse range of sound qualities of the human voice accomplished?

Answer 10

Modulation of the vibration pattern of the vocal folds

Question 11

The primary elements involved in vocal fold/voice modulations include how many cartilages and how many muscles?

Answer 11

3 Cartilages

5 Muscles

Question 12

What are the 3 cartilages involved in voice modulation?

Answer 12

Thyroid cartilage
Arytenoid cartilage
Cricoid cartilage

Question 13

Which is the largest cartilage of the larynx: thyroid, arytenoid, or cricoid?

Answer 13

Thyroid

Question 14

Which type of cartilage is formed by 2 plates that join at the front of the throat (Adam’s apple)?

Answer 14

Thyroid cartilage

Question 15

The _____ (anterior/posterior) end of the vocal folds attach to the _____ (inside/outside) of the thyroid cartilage

Answer 15

The anterior ends attach to the inside of the thyroid cartilage

Question 16

What type of cartilages consist of a pair of small pyramid shaped cartilages that sit at the posterior edge of the thyroid cartilage?

Answer 16

Arytenoid cartilages

Question 17

The arytenoid cartilages sit on top of what cartilage?

Answer 17

The cricoid cartilage

Question 18

The vocal folds stretch between which two cartilages?

Answer 18

Thyroid and Arytenoid

Question 19

Which voice modulation cartilage is shaped like a signet ring, and which way does the “wide” side face?

Answer 19

Cricoid cartilage - the wide side is at the back, and the narrow side is at the front

Question 20

Which type of cartilage forms a ring, and is the lowest of the 3 types of cartilages involved in voice modulations?

Answer 20

Cricoid cartilage

Question 21

The thyroid and arytenoid cartilages attach and form joints where?

Answer 21

On the back of the cricoid

Question 22

Which joint allows the arytenoids to rotate, rock, and slide in a wide range of directions, and plays an important role in allowing for changes in the position of the vocal folds?

Answer 22

The cricoarytenoid joint

Question 23

What does the cricothyroid joint allow for?

Answer 23

The up and down tilting of the thyroid cartilage - this plays a role in allowing for stretching of the vocal folds

Question 24

What are the 5 primary intrinsic laryngeal muscles?

Answer 24

Posterior cricoarytenoid (PCA) muscle
Lateral cricoarytenoid (LCA) muscle
Interarytenoid (IA) muscle
Cricothyroid (CT) muscle
Thyroarytenoid (TA) muscle)

Question 25

Which muscle opens the vocal folds (abduction)? What are its points of attachment?

Answer 25

PCA (Posterior Cricoarytenoid) Muscle Originates on posterior of cricoid cartilage Inserts on muscular process of arytenoid cartilage -> rotates arytenoids outwards

Question 26

Which muscles close the vocal folds (adduction)? What are their points of attachment?

Answer 26

LCA (Lateral Cricoarytenoid) Muscle - Originates on lateral border of cricoid cartilage - Inserts on muscular process of arytenoid cartilage - > rotates arytenoids inwards and closes the vocal folds IA (Interarytenoid) Muscle - posterior surface of the arytenoids - > pulls them together, thus pulling the vocal folds together

Question 27

Which muscles are responsible for tensing and lengthening the vocal folds? What are their points of attachment?

Answer 27

CT (Cricothyroid) Muscle - originates on the lateral surface of the cricoid cartilage - inserts on the lower edge of the thyroid cartilage - > pulls the thyroid cartilage forwards and downwards, thereby tensing and lengthening the vocal folds and raising the pitch TA (Thyroarytenoid) Muscle - originates on the vocal process of the arytenoid cartilage - inserts on the angle of the thyroid - (forms the main mass of the true vocal folds) - > can stiffen and tense the vocal folds (can change vocal pitch and quality)

Question 28

Explain the Myoelastic-Aerodynamic Theory of Phonation

Answer 28

``` Myo = muscle Elastic = tissue elasticity Aerodynamic = air pressure and flow ``` - widely accepted model of phonation - states that, to produce phonation: 1) vocal folds adducted by continuously contracting LCA and IA (process called medial compression) 2) subglottal pressure builds up to ~3-5 cmH2O 3) pressure forces vocal folds apart 4) rapid opening of vocal folds causes rapid flow of air through opening 5) rapid flow produces negative air pressure between vocal folds, pulling them back together (Bernoulli effect) 6) vocal folds also pulled back together by elastic recoil of vocal fold tissues and continuous closing muscle contractions 7) once vocal folds are closed, cycle repeats, again and again

Question 29

The process of negative air pressure, produced by the rapid flow of air through the vocal folds, pulling the vocal folds back together is know as the _____ Effect

Answer 29

Bernoulli

Question 30

What is medial compression?

Answer 30

The continuous contraction of the closing muscles (LCA and IA) to bring the vocal folds together (adduction)

Question 31

The vocal fold tissues are made up of how many layers?

Answer 31

5

Question 32

What are the 5 tissue layers of the vocal folds?

Answer 32

Cover: Epithelium and Superficial Layer of the Lamina Propria Transition: Intermediate Layer of the Lamina Propria and Deep Layer of the Lamina Propria Body: Thyroarytenoid or Vocalis Muscle

Question 33

What does the Cover Body Model refer to?

Answer 33

The stiffness of the cover layer and the body layer being able to be adjusted somewhat independently by contracting different muscles (ie. CT versus TA), which allows for a complex variety of voice qualities to be produced

Question 34

True or False: Complex layering causes the vocal folds to vibrate in simple, predictable patterns

Answer 34

False - it causes the vocal folds to vibrate in a complex pattern (both vertical and longitudinal waves)

Question 35

Explain what is meant when we say that there are vertical and longitudinal phase differences in the motion of the vocal folds?

Answer 35

During vocal fold vibration, there is a time lag between the opening and closing of: - the inferior and superior portions of the folds (=vertical phase difference), and - the anterior and posterior portions of the folds (=longitudinal phase difference) The folds open from bottom to top and from posterior to anterior, and close from bottom to top and from anterior to posterior

Question 36

What is a glottogram used for?

Answer 36

Measurement of the vocal fold opening and closing

Question 37

What is the glottis?

Answer 37

The opening between the vocal folds

Question 38

What are 3 visual methods for assessing the vocal folds?

Answer 38

High Speed Cinematography Video Stroboscopy Electroglottography (EGG)

Question 39

How does High Speed Cinematography work?

Answer 39

- laryngoscope placed at back of the throat to view the vocal folds - high speed film (4000 frames/sec) allows for 20-40 pics across each cycle of vocal fold vibration - distance between vocal folds or area of vocal fold opening can be measured

Question 40

Which visual method for vocal fold assessment takes pictures of the vocal folds in synchrony with a flashing light, taking only one picture of each cycle of vibration?

Answer 40

Video Stroboscopy -if the flashing frequency is slightly slower than the fold vibration frequency, the result is a slow motion movie of the vibration cycle

Question 41

What information can be obtained through video stroboscopy?

Answer 41

Distance between vocal folds Area of glottis Vocal fold movement patterns

Question 42

What does EGG stand for?

Answer 42

Electroglottography

Question 43

How does electroglottography work?

Answer 43

- 2 electrodes placed on either side of neck (on plates of thyroid) - resistance and flow of electricity across the larynx/glottis changes as folds open and close - electrical resistance changes shown as continuous waveform (reflect glottal opening)

Question 44

What type of information can be obtained from an EGG?

Answer 44

Ratio of open/closing time Closed phase duration Slope of closing phase

Question 45

True or False: Voice disorders are often associated with abnormal EGG measures

Answer 45

True