Handout 4: Phonatory/laryngeal system

Question 1

vocal folds are

Answer 1

a valve in the airway at the level of the larynx (see Fig. 4.9 (5.8))

• a pair of structures that are each composed of epithelial tissue, mucus membrane, and muscle tissue
• primary role of the vocal folds in speech is to vibrate and thus generate the voice signal (one of the primary components of most speech sounds)

Question 2

vocal folds role in nonspeech activities

Answer 2

protecting the airway (closing during swallowing, coughing) and assisting in strenuous lifting or pushing

Question 3

the false vocal folds and epiglottis, located above the vocal folds also play an important role in …

Answer 3

closing and protecting the airway during swallowing but they have a very minor role in normal speech/voice

Question 4

the vibraton of the vocal folds is a result of

Answer 4

the vocal folds continuously alternating between coming together (closed) and pushing apart (opened)

Question 5

phonation

Answer 5

the vibration pattern of the vocal folds

Question 6

the vibration of the vocal folds can be modified to…

Answer 6

accomplish the highly diverse sound qualities of the human voice (loud, soft, whisper, high, low, rough, smooth, hoarse, harsh, breathy, etc.)

Question 7

the primary elements involved in vocal fold/voice modulations include ___ cartilages and ___ muscles

Answer 7

3, 5

Question 8

thyroid cartilage

Answer 8

largest cartilage of the larynx (Figures 4.1-4.4 (5.1-5.4))

• formed by 2 plates that join at the front of the throat (Adam’s apple)
• the anterior end of the vocal folds attach to the inside of the thyroid cartilage

Question 9

arytenoid cartilages

Answer 9

• a pair of small pyramid shaped cartilages that sit at the posterior edge or the thyroid cartilage and sit on the top of cricoid cartilage
• the posterior end of the vocal folds attach to the arytenoid cartilages
• thus the vocal folds stretch between the thyroid and arytenoids cartilages

Question 10

cricoid cartilage

Answer 10

• a complete ring of cartilage that is just below the thyroid and arytenoids cartilages
• shaped like a signet ring
• the thyroid and arytenoids cartilages attach and form joints on the back of the cricoid

Question 11

cricothyroid joint

Answer 11

allows for up and down tilting of the thyroid cartilage – plays a role in allowing for stretching of the vocal folds

Question 11

cricoarytenoud joint

Answer 11

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

Question 12

which muscle opens the vocal folds (abduction)

Answer 12

posterior cricoarytenoud muscle - causes the arytenoids to rotate outwards and open folds

Question 13

what two muscles close the vocal folds (adduction)

Answer 13

lateral cricoarytenoid
interarytenoid

Question 14

lateral cricoayrtenoid causes the

Answer 14

arytenoids to rotate inwards and closes the vocal folds

Question 15

the interarytenoid muscles causes the

Answer 15

arytenoids to be pulled together, pulling the VFs together

Question 16

the two tensing and lengthening muscles of the VFs are

Answer 16

cricothyroid muscles
thyroarytenoud muscle

Question 17

the cricothyroid muscle does what

Answer 17

pulls the thyrid cartilage forward and down - tenses/lengthens the VFs which raises pitch

Question 18

thyroarytenoud muscle does what

Answer 18

can stiffen and tense the VFs - Chang vocal pitch and quality

Question 19

myoelastic-aerodynamic theory of phonation is

Answer 19

• a widely accepted model of phonation that was proposed about 40 years ago
• describes voice production as a combination of muscle forces (myo), tissueelasticity (elastic), and air pressures and flows (aerodynamic)

Question 20

medial compression

Answer 20

To initiate phonation the vocal folds are brought together (adducted) by continuously contracting the closing muscles (LCA and IA)

Question 21

what happens once the VFs are closed

Answer 21

the subglottal pressure begins to build up quickly

Question 22

when the subglottal pressure reaches 3-5 cmH2O what happens

Answer 22

forces vocal folds apart

Question 23

rapid opening of the vocal folds causes

Answer 23

• rapid air flow thru which results in neg air pressure bw the folds

Question 24

bernoulli effect

Answer 24

The rapid flow produces a negative air pressure to develop between the vocal folds and this causes the vocal folds to be pulled back together

Question 25

the vocal folds get pulled back together bc of the bernoulli effect and because of

Answer 25

the elastic recoil of the vocal fold tissues and the continuous closing muscle contractions

Question 26

how many layers of tissue in the vocal folds

Answer 26

5

Question 27

what are the 5 layers of the vocal folds

Answer 27

1 - epithelium
2- superfifical layer of the lamina propria
3- intermediate layer of the lamina propria
4. deep layer of the lamina propria
5. thyroarytenoid muscle

Question 28

what is the cover body model and what does it allow for?

Answer 28

stiffness of the cover layer and body layer can be adjusted somewhat independently by contracting diff muscles

this allows for a complex variety of voice qualities to be produced

Question 29

complex layering of the VFs also causes the vocal folds to vibrate in a complex pattern…. observation of microdynamics of vibration reveal ….

Answer 29

both vertical waves and longitudinal waves during VF vibration

Question 30

how is the vertical wave reflected?

Answer 30

vertical phase difference –> a time lag bw the opening and closing of the inferior and superior portions of the folds

Question 31

how do the VFs open/close in the vertical dimension

Answer 31

open= bottom to top (inferior to superior)
close = bottom to top (inferior to superior)

Question 32

the longitudinal wave is reflected by…

Answer 32

a time lag bw the opening and closing of the anterior and posterior portions of the VFs

Question 33

how do the VFs open/close in the longitudinal direction

Answer 33

open = back to front (posterior to anterior)
close = front to back (anterior to posterior)

Question 34

glottogram is a measurement of

Answer 34

vocal fold opening and closing

Question 35

glottis

Answer 35

opening bw the vocal folds

Question 36

what are the 3 ways to measure the glottis

Answer 36

high speed cinematography

video stroboscopy

electroglottography (EEG)

Question 37

high speed cinematography

Answer 37

– laryngoscope placed at the back of the throat to view the vocal folds

– high speed film (4000 frames per second) allows for 20-40 pictures across each cycle of vocal fold vibration

– distance between the vocal folds or the area of the vocal fold opening can be measured

Question 38

video stroboscopy

Answer 38

• takes pictures of vocal folds in synchrony with a flashing light
• only one picture is taken of each cycle of vibration
• if the flashing frequency is slightly slower than the fold vibration frequency the result is a slow motion movie of the vibration cycle
• distance between the folds, area of glottis, and vocal fold movement patterns can be obtained

Question 39

electroglottography (EGG)

Answer 39

• two electrodes placed on either side of the neck (on the plates of the thyroid)
• as the folds open and close there is a change in the resistance and flow of electricity across the larynx/glottis
• the changes in electrical resistance can be shown as a continuous waveform (reflecting glottal opening)
• waveform measures such as the ratio of opening/closing time, closed phase duration, and slope of the closing phase are example of 3 types of measures that are often obtained from the EGG
• voice disorders are often associated with abnormal EGG measures