A&P Exam 2 Physiology

Question 1

What is phonation?

Answer 1

Any type of laryngeal sound production in speech. Involves the conversion of potential energy of compressed air into kinetic energy of acoustic vibration.

Question 2

Source theories: Galen

Answer 2

200 AD. Thought trachea was the central origin of voice and acted like a flute or vibrating column or air.

Question 3

Source theories: Dodart

Answer 3

1700. Thought larynx was the origin of voice, and vocal folds changed cavity size like tongue and lips change pitch in whistling.

Question 4

Source theories: Ferrein

Answer 4

1740. Vocal folds work like a stringed instrument, with the movement of the string vibrating the air.

Question 5

Source theories: Helmholtz

Answer 5

1860. Laryngeal sound source related to puffs of air escaping through glottis. Valving (turning on/off) of airstream produces sound.

Question 6

What is the neurochronaxic theory?

Answer 6

Says that action potentials from the brain cause the vocalis muscle to twitch on a cycle-by-cycle basis, making the frequency of vocal fold vibration dependent on the rate of neural impulses delivered to the laryngeal musculature.

Question 7

Why is the neurochronaxic theory wrong?

Answer 7

1. Brain can’t send signals fast enough to account for speed of vocal fold vibration
2. Muscle fiber orientation doesn’t explain adduction
3. Signal to each vocal fold would be mismatched because right and left nerves are different lengths
4. Thumping someone’s chest causes phonation without neural imput
5. Phonation can be produced by airflow without neural imput (cadaver larynx will phonate)

Question 8

What is the aerodynamic-myoelastic theory?

Answer 8

Elastic vocal folds are moved back to adducted position by:

1. myoelasticity: elastic recoil similar to recoil of lung-thorax unit
2. aerodynamic forces: Bernoulli effect

Question 9

Bernoulli effect

Answer 9

Given a constant volume of flow of air, at a point of constriction there will be a decrease in pressure perpendicular to the flow and an increase in velocity of the flow. The greater the flow, the greater the suction.

Question 10

How does the Bernoulli effect apply to phonation?

Answer 10

Question 11

How do the vocal folds blow apart/come together (vertical dimension)?

Answer 11

Both blow apart and come together from inferior to superior (below to above)

Question 12

3 states of phonation

Answer 12

1. Ready: adduct vocal folds in the stream of airflow (vocal attack)
2. Go: hold folds in fixed position in airstream and actual vibration results in sustained phonation
3. Stop: abduct vocal folds to terminate phonation

Question 13

Simultaneous vocal attack

Answer 13

Adduction of vocal folds and onset of respiration occur simultaneously (happens when you say “zany”)

Question 14

Breathy vocal attack

Answer 14

Airflow starts prior to adduction of vocal folds (happens when you say “Harry”).

Question 15

Glottal attack

Answer 15

Adduction of the vocal folds occurs prior to airflow (happens when you anticipate a cough, but talk instead).

Question 16

What portion of time is spent in each of the vibratory stages?

Answer 16

• Opening: 50%
• Closing: 37%
• Closed: 13%

Question 17

What is pitch?

Answer 17

The psychological correlate (what we percieve) of frequency of vocal fold vibration. As frequency increases, pitch increases.

Question 18

Fundamental Frequency

Answer 18

Frequency of vibration of sustained phonation.

Question 19

Optimal pitch

Answer 19

Frequency of vocal fold vibration that is most appropriate for an individual, integrating mass, elasticity, and length of vocal folds

• about 1/4 octave above the lowest frequency of vibration
• ~212 Hz in females
• ~132 Hz in males

Question 20

Habitual pitch

Answer 20

The frequency of vocal fold vibration used during speech (ideally the same as optimal pitch).

Question 21

Pitch range

Answer 21

From highest to lowest possible frequencies.

Question 22

How do the vocal folds blow apart/come together (from a superior view)?

Answer 22

• Open: posterior to anterior
• Close: anterior to posterior

Question 23

Pitch-changing Mechanism: Tension

Answer 23

Involves tightening/relaxation of muscles

• Major adjustments: cricothyroid tilts thyroid down in front and lengthens VFs
• Minor tweaks: thyrovocalis stretches for increased tension
• Increased tension = Increased pitch

Question 24

Pitch-changing Mechanism: Mass

Answer 24

Spread out mass by stretching/lengthening the vocal folds (using cricothyroid and vocalis)

• Increased mass = decreased pitch

Question 25

Pitch-changing Mechanism: Subglottal Pressure

Answer 25

Increasing glottal resistance to airflow due to increased tension requires increased airflow

• Higher air pressure = higher pitch

Question 26

Intensity

Answer 26

The physical measure of pressure ratios

Question 27

Loudness

Answer 27

The psychological correlate of intensity (how we percieve intensity)

Question 28

How does sublgottal air pressure influence intensity?

Answer 28

Higher subglottal air pressure = higher intensity

Question 29

How does medial compression influence intensity?

Answer 29

When VFs are tightly compressed, more energy is required to blow them apart, and when they do, it produces an explosive compression of the air. This leads to a greater amplitude of a cycle of vibration, which we hear as increased intensity.

• Higher medial compression = higher intensity

Question 30

How are intensity and frequency related physiologically?

Answer 30

They are controlled independently and one can be manipulated without changing the other. However, both depend on the same mechanisms, so it’s difficult to increase intensity without increasing pitch.

Question 31

Order from lowest to highest (average) fundamental frequency: adult female, adult male, child.

Answer 31

Lowest to highest: adult male, adult female, child

Question 32

Why does frequency vary with age and gender?

Answer 32

Adults have a larger larynx than children, and vocal folds that are longer or have more mass will vibrate more slowly. Males also tend to have a larger larynx than do females.

Question 33

Suprasegmental

Answer 33

Above the segmental (phonetic) level. Includes elements of prosody.

Question 34

Prosody

Answer 34

Varied stress, pitch, intonation, loudness, duration, or rhythm used to indicate meaning.

Question 35

Cover-Body Theory

Answer 35

Tthe cover of the vocal folds (the mucosal lining) is considered separately from the body (the muscle). Fundamental frequency is determined by the cover independently of the body. For example:

• when the cricothyroid muscle contracts, it stretches both the cover and the body, increasing fundamental frequency
• when the thyrovocalis alone contracts, it tightens the body but releases the cover, increasing effective mass and decreasing fundamental frequency