Voice

Question 1

Where is the hyoid bone located?

Answer 1

Anterior midline of neck, between mandible and thyroid cartilage. At rest it is at the level of the base of the mandible in front and the C3 vertebra behind. (pg 21 & 22 textbook)

Question 2

2. Where is the cricoid cartilage located?

Answer 2

The ring of cartilage surrounding the trachea, located in the middle and centre of neck. inferior to thyroid cartilage at level of C6 Vertebra. (pg 24 textbook)

Question 3

Is the oesophagus behind or in front of the trachea?

Answer 3

It connects the pharynx with the stomach and is behind the trachea and infant of the spine

Question 4

4. What is the function of the soft palate?

Answer 4

It has multiple functions:

During swallowing it rises to close off the nasal passages and airway to stop food entering the nasopharynx

Protects nasal passage during sneezing

It contains the uvula which elicits the gag reflex

Aids speech, the pronunciation of velar consonants.

Question 5

5. Where are the arytenoids cartilages located?

Answer 5

Pair of little pyramidal cartilages found in the larynx. Vocal cords are attached to them. Located at the dorsal side of larynx above cricoid lamina. (pg 25 textbook)

Question 6

6. What does the laryngeal abductor muscle do?

Answer 6

Posterior cricoarytenoid muscle. The only muscle to open the vocal folds, By rotating the arytenoid cartilages laterally and widening the rima glottis. (lecture 1: slide 14/15) (page 38 textbook)

Question 7

7. What do the laryngeal adductor muscles do?

Answer 7

Close the vocal folds. (lecture 1: slide 14/15) (pg 34-37 textbook)

Lateral cricoarytenoid muscles are the major adductors of the vocal folds. This narrows the rima glottis, modulating the tone and volume of speech.

transverse and oblique arytenoids muscles adduct the arytenoid cartilages, closing the posterior portion of rima glottis. This narrows the laryngeal inlet.

Question 8

8. What is the name of an abductor laryngeal muscle?

Answer 8

Posterior cricoarytenoid muscle (lecture 1: slide 14/15)(page 38 textbook)

Question 9

Q 9. How does the pitch-raising muscle actually work to increase pitch? What is its physical action?

Answer 9

The cricothyroid muscle contracts causing the vocal folds to lengthen (Stemple p.49). It draws the thyroid down and forward, closer to cricoid cartilage, resulting in lengthening and tensing of the vocal folds (workbook. section 1. P.7).

Question 10

Q 10. On a diagram of the larynx, differentiate between the location of the lateral cricoarytenoid muscle and the cricothyroid muscle.

Answer 10

Question 11

Q 11. Where is the thyroid gland located, in relation to the thyroid cartilage?

Answer 11

The thyroid gland sits inferiorly to the thyroid cartilage (butterfly shaped).

Question 12

Q 12. What is the function of the false vocal folds?

Answer 12

To create a strong adduction for forceful closures such as coughing, grunting, or swallowing. (Stemple, p. 34)

Question 13

Q 13. On a diagram of the larynx, point to where the posterior cricoarytenoid muscle is located.

Answer 13

Question 14

Q 14. Which intrinsic laryngeal muscle is not a PAIRED muscle?

Answer 14

The transverse arytenoid muscle.

Question 15

Q 15. What two branches of the vagus nerve are concerned with laryngeal function?

Answer 15

The recurrent laryngeal nerve (RLN) and the superior laryngeal nerve (SLN). (Stemple, p. 43)

i. Superior laryngeal nerve – receives general sensory information from superior laryngeal mucosa and superior aspect of vocal folds and motor to the cricothyroid muscle
ii. Recurrent laryngeal nerve – receives general sensory information from all intrinsic muscles and inferior laryngeal mucosa and vocal folds, and provides motor function to intrinsic muscles (except for cricothyroid)

Question 16

Q 16. Why is the layered structure of the vocal fold tissues important for voice?

Answer 16

The intact layered structure is critical for an efficient mucosal wave, that creates a clear vocal tone during phonation. (SPH511 lecture slide)

Question 17

Q. 17. What are the five layers of the tissue of the vocal folds?

Answer 17

• epithelium (stratified squamous) - which is the outer layer.
• superficial lamina propria
• intermediate lamina propria
• deep layer of lamina propria
• vocalis muscle

(slide 17 Alison’s lecture notes: voice basics)

Question 18

Q 18. What are the three functional layers of the vocal fold tissues

Answer 18

• Cover which is the epithelium
• Lamina propria which is comprised of:

o Superficial layer

o Intermediate

o Deep layer

• Body which is the vocolis muscle.

(slide 17 Alison’s lecture notes: voice basics)

Question 19

Q 19. If we look down the throat of a patient, does the epiglottis close downwards in swallowing towards the front or back?

Answer 19

When a person is swallowing their epiglottis moves inferiorly (down towards feet) and posteriorly (towards the back of the body) over their larynx to protect their airway (p. 23 textbook)

Question 20

Q 20. What is the Bernoulli or venturi effect, in relation to vocal fold vibration?

Answer 20

Vocal fold vibration happens as a result of bernoulli’s effect which states that when dealing with liquid or gas an increase in velocity is accompanied by a decrease in pressure. Once the vocal folds are brought together the air from the lungs creates a subglottic pressure which forces the bottom of the vocal folds to open this air continues to move up causing the top of the vocal folds to open. The low pressure created by the fast-moving air column acts like a suction and causes the bottom of the vocal folds to close followed by the top. This happens repeatedly and very quickly causing the vocal folds to vibrate.

(taken from https://voicefoundation.org/health-science/voice-disorders/anatomy-physiology-of-voice-production/understanding-voice-production/)

Page 54 of the textbook also has information on this.

Here is a clip that shows the vibration in action

https://www.youtube.com/watch?v=y2okeYVclQo

Question 21

Q 21 How are adduction and abduction of the vocal folds different to vocal fold vibration?

Answer 21

Vocal fold vibration is caused by the Bernoulli effect and no muscles are involved in the movements. Vocal fold vibration is for phonation. Vocal fold adduction and abduction is a result from intrinsic laryngeal muscles opening and closing the vocal folds. Vocal fold vibration can only happen once the vocal folds are adducted. (page 17 workbook).

Question 22

22. Why do the vocal folds need to be closed in order for the voice to work?

Answer 22

If the vocal folds are open, there is nothing to vibrate. Having closed vocal folds allows them to be blown apart from subglottic pressure causing the vibration which in turn causes the sound source for phonation. (page 2 of the textbook).

Question 23

Q23. Why do men have a lower pitched voice than women?

Answer 23

During Puberty all the dimensions in a boys larynx change in size including the vocal folds which increase in mass and length. This causes males to have a deeper voice than women as their vocal folds aren’t as long. Even though the females larynx also grows it does not grow to the same extent as a males. (voice workbook page 18).

Question 24

24. Why is the voice hoarse when we get a cold? What causes hoarseness?

Answer 24

Hoarseness is a result of inflammation or infection which impacts the vocal folds. The infection causes the vocal folds to swell and they may become irritated. It is often associated with laryngitis and is generally treated by resting. Drinking water is important for hydration and reducing irritation of the vocal folds.

Question 25

25. Why is maximum phonation time (MPT) a useful measure in a voice assessment?

Answer 25

MPT gives an indication of respiration quality during speech. It can be used as a tool to demonstrate voice improvement with pre-test and post-test measures (Stemple, Roy & Klaben, 2020, p.155).

Question 26

26. What are the limitations of MPT, as a voice assessment task?

Answer 26

Airflow volume during MPT tasks is not correlated with measures with lung function and therefore can’t accurately estimate lung volume.

Question 27

27. What are some ways we can make the voice louder? Explain physiologically.

Answer 27

We use the Bernoulli principle to build pressure at the subglottal level (vocal folds closed) and then release the air with force. The intensity of our voice is related to the lateral abduction of the vocal folds and how quickly they adduct, which is a function of the subglottal air pressure and the resulting airflow.

The suprahyoid (extrinsic laryngeal) muscles contribute to loudness by elevating the larynx and changing the shape and “filtering characteristic” (Stemple et al., 2020, p.30) of the vocal tract for phonation.

Question 28

28. Name and locate 3 extrinsic laryngeal muscles

Answer 28

• Stylohyoid – attaches to the styloid process of the temporal bone superiorly and they hyoid bone inferiorly. It is a suprahyoid muscle.
• Mylohyoid – attaches to the mandible superiorly and the hyoid bone inferiorly. It forms the floor of the oral cavity. It is a suprahyoid muscle
• Sternothyroid – attaches to the sternum inferiorly and the thyroid cartilage superiorly. It is an inferior hyoid muscle

Question 29

29. Why are extrinsic laryngeal muscles important for voice? What are some of the implications for voice disorders?

Answer 29

Extrinsic laryngeal muscles elevate and depress the larynx for airway protection. The suprahyoids elevate the muscles, allowing the epiglottis to close over the glottis for airway protection and changing the shape of the supraglottal vocal tract, which then modifies pitch, loudness and quality. The infrahyoids depress the larynx. If particular muscles are too tight or don’t contract, this function is impaired. Ie. The epiglottis may not cover the airway.

“Laryngeal elevation during phonation may be a sign of excessive intrinsic laryngeal muscle tension and is an accurate indicator of hyperfunctional voice use. (Stemple et al., 2020, p.31-32).

Question 30

30. Name and locate the extrinsic tongue muscles

Answer 30

• Genioglossus - Its arises from the mental spine of the mandible and its insertions are the hyoid bone and the bottom of the tongue
• Hyoglossus – quadrilateral muscles located on the lateral sides of the tongue. Meets the hyoid bone inferiorly
• Styloglossus – Insertion is the styloid process of the temporal bone superiorly and blends with the fibres of the inferior longitudinal muscle of the tongue near the hyoglossus
• Palatoglossus – originates from the bottom part of the palatine aponeurosis and moves laterally to join with the intrinsic muscles of the tongue

Question 31

31. Locate the inferior laryngeal constrictor muscle, in relation to superior and middle pharyngeal constrictors

Answer 31

It is located beneath the superior and middle pharyngeal constrictors and arises from the sides of the thyroid and cricoid cartilages.

Question 32

32. What is the significance of the thyrohyoid space?

Answer 32

The thyrohyoid membrane stretches from the thyroid cartilage to the hyoid bone. It creates a hollow tube, that may be the supra-epiglottic space.

Either that, or it is a made up space!!

Question 33

33. For a voluntary cough, the vocal folds have to be able to close tightly: true or false?

Answer 33

True

When you cough, you usually take a breath in first, then the folds close tightly. The breath in the lungs builds up a lot of pressure against the closed folds. This pressure is suddenly released with enough force to expel anything loose in the supraglottic area, or airway, is forced into the mouth, and can be spat out or swallowed.

(Voice Workbook, SPH512, p 19)

Question 34

34. Breathing is different during connected speech (compared to quiet breathing) in that inspiratory times are much fast and expiratory times are much longer. True or false?

Answer 34

True

During connected speech, the inspiration breath is very quick, and the expiration (talking) breath extends for longer than during quiet breathing. This allows for longer vibration of the vocal folds which results in the ability to talk for a longer time. The air is slowly released during speech. Speech uses very little of our respiratory capacity during connected speech.

(Voice workbook, PSH512, p.19)

When you talk, you automatically take in the right amount of breath for what you want to say. (Voice workbook, SPH512, p. 26)

Different to reading aloud, where we tend to take in breaths at punctuation points. (Voice workbook, SPH512, p. 26)

Question 35

When you shout, the pitch of your voice naturally decreases. True or false?

Answer 35

False

The pitch of your voice increases. [I guess this means that the cricothyroid muscle rocks the thyroid cartilage forward, putting more strain on the vocal ligament, causing the vibrations to decrease in size, but increase in frequency.

Does shouting involve a building up subglottic pressure?

Question 36

What is the significance of the hyoid bone, in relation to the laryngeal function in voice and swallowing?

Answer 36

Voice: the hyoid bone serves as an attachment point for the extrinsic muscles of the larynx, resulting in the larynx being ‘suspended’ in the throat region. This arrangement allows the larynx to move superiorly and inferiorly during speech. The extrinsic muscles influence the overall position of the larynx in the neck (Clinical Voice Pathology, p30).

Swallowing: the supra- and infrahyoid muscles all attach to this bone (exception – sternothyroid). During swallowing, the muscles pull the hyoid bone up and forward, forcing the epiglottis down to cover the laryngeal opening. This action also opens the UES to allow food and fluid to enter the oesophagus.

Question 37

What is medial compression of the vocal folds?

Answer 37

This is where the vocal folds come together tightly to allow subglottal pressure to build up, ready for phonation, sneezing, coughing

They also come together as an added line of defence when swallowing, or participating in effortful activities, such a weight lifting (Clinical Voice Pathology, p. 17-18)

Question 38

What is the most commonly presenting voice disorder, in clients referred to speech pathology (adults)?

Answer 38

Functional dysphonia (20.5%), acid laryngitis (12.5%), vocal polyps (12%) in adults

Think a large number of individuals don’t seek medical assistance for voice disorders, making the true statistics hard to evaluate

In adults, more females present with voice disorders than males

(ASHA: Voice disorders; retrieved on 26th May, 2019) https://www.asha.org/PRPSpecificTopic.aspx?folderid=8589942600&section=Incidence_and_Prevalence

Question 39

4. What is the function of the epiglottis?

Answer 39

The main function of the epiglottis is to seal off the windpipe during eating, so that food is not accidentally inhaled

Question 40

5. A person has little control over the habitual pitch of their speaking voice: habitual pitch is innate: true or false?

Answer 40

False. We can vary the pitch of our speaking voice easily. Habitual pitch is not innate. Although there are limitations to the pitch imposed by our anatomy and our abilities, we can vary our speaking pitch to a large extent. We control the pitch of our voice all the time – whenever you use normal intonation in saying a sentence, you are varying the pitch of your voice. And if you wanted to, you could change the overall pitch of your speaking voice to be a bit higher or lower.

Question 41

6. How do we breathe during speech?

Question 42

7. What kind of epithelium makes up the outermost layer of the vocal folds?

Answer 42

Epithelium is the surface skin of the larynx. The free edge of the vibratory portion of the vocal fold, the anterior glottis, is covered with stratified squamous epithelium.

Question 43

8. Why do we say that the cricothyroid muscle acts on the voice “indirectly”?

Answer 43

It aids with phonationas it moves the thyroid forward and tenses the vocal cords.