Phonation

Question 1

Define phonation

Answer 1

The production of sound by modulating the movement of air through the vocal cords of the larynx

Question 2

Why is phonation needed?

Answer 2

to produce the vowels and voiced consonants which make up 2/3rds of the english language

Question 3

What are the conditions for phonation?

Answer 3

1. flow of air from lungs
2. adduction of vocal folds
3. tension in vocal folds

Question 4

What is the aerodynamic myoelastic theory?

Answer 4

1. air comes up from lungs
2. vocal folds adduct
3. subglottal pressure builds until it exceeds force of muscle tension used to adduct vocal folds
4. small amount of air rushes through vocal folds and sublottal pressure falls again

Question 5

What is the Bernoulli effect?

Answer 5

High velocity air or liquid causes low pressure, which pushes/pulls objects
The rush of air escaping the vocal folds at high velocity causes low pressure, sucking the vocal folds back in together

Question 6

What is the complex pattern of vocal fold movement?

Answer 6

1. vocal folds open and close from bottom up
2. complex vibration along length resulting in fundamental frequency and formants
3. causes small puffs of air to be released in the vocal tract

Question 7

Which muscles adduct the vocal folds?

Answer 7

1. interarytenoids
2. lateral cricoarytenoid muscles

Question 8

What are the variants in voicing?

Answer 8

1. frequency
2. intensity
3. quality

Question 9

Define frequency

Answer 9

Number of vibrations per second, affecting what we perceive as pitch

Question 10

How is frequency range determined?

Answer 10

By the resting length and thickness of vocal folds

Question 11

Alterations in pitch depend on which parameters?

Answer 11

1. length (max elongation about an extra 20%)
2. thickness (can change by factor of 2)
3. tension

Question 12

How does length affect pitch?

Answer 12

increase length = increased pitch

Question 13

How does thickness effect pitch?

Answer 13

increase thickness = decreased pitch

Question 14

How does tension affect pitch?

Answer 14

increase tension = higher number of vibrations = increased pitch

Question 15

What happens if you change one parameter of pitch?

Answer 15

the other 2 also change

Question 16

Which muscles change length and thickness of vocal folds?

Answer 16

1. thyroarytenoids
2. vocalis
3. cricoarytenoids = thyroarytenoids if they cintract isometrically

Question 17

Define intensity

Answer 17

perceived loudness

Question 18

What is typical intensity?

Answer 18

1. normal speech varies over 30 decibels
2. a shout can reach 70 decibels

Question 19

What causes increased intensity?

Answer 19

1. increased subglottal pressure (each doubling increases intensity by around 10 decibels)
2. vocal folds are blown apart quicker with more force
3. vocal folds must then close for longer to dissapate the extra energy

Question 20

Which muscles are used to alter intensity?

Answer 20

1. interarytenoids and cricoarytenoids control subglottal pressure
2. may also use cricothyroid and cricoarytenoid

Question 21

What can cause growths on the vocal folds?

Answer 21

direct effect of disease affecting larynx or manner of use

Question 22

What causes vocal nodes?

Answer 22

increased loudness casuses stronger adduction which causes trauma to contact points of vocal folds which can cause vocal nodes

Question 23

What organic diseases can affect voice?

Answer 23

1, thyroid hormone deficiency = thickening of vocal folds from oedema so lower pitch
2. osteoarthyritis = can affect laryngeal joints

Question 24

What neuromuscular issues can affect voice?

Answer 24

stroke, cerebellar ataxia, parkinsons

Question 25

What causes nerve palsy?

Answer 25

1. 90% bronchial carcinoma in left lung 2. 10% thyroid surgery

Question 26

How does laryngeal nerve palsy affect voice?

Answer 26

All muscles paralysed except arycothyroid and interarytenoids = tense partial adduction = harsh raspy voice

Question 27

How can drugs affect voice?

Answer 27

May affect neuromuscular control, cause excess mucous production which 'thickens' vocal folds