Physiology of the Phonatory system

Question 2

Layered Structure of the Vocal Folds: Five Layers

Answer 2

• (superficial)
• Epithelium
• Superficial L.P.
• Intermediate L.P.
• Deep L.P.
• Vocalis Muscle
• (deep)

Question 3

Vocal Cords

Answer 3

Question 6

Phonation (+ KEY POINTS)

Answer 6

•A self sustaining, quasi-periodic oscillation of the vocal folds that results from the interaction of muscular and aerodynamic forces in the vocal tract

Key points:

• Self sustaining
• Quasi-periodic oscillation
• Interaction of muscular & aerodynamic forces

Question 7

Voice is…

Answer 7

• A series of puffs of air separated by closure of the vocal folds between each “puff”
• The “puffs of air” reflect local changes in air pressure (compression, rarefaction)

Question 8

Vocal Fold as a Valve

Answer 8

• Vocal folds are major source of periodic vibration for the production of sound for speech
• Vocal folds act as regulating valve because of their close mid-line approximation. They let small puffs of air pass through the glottis, one at a time.
• Act as an interruption of the airflow source

Question 9

medial compression

Answer 9

• Forces that act to approximate vocal folds at midline
• Combination of LCA and IA to rotate arytenoids

Question 10

Longitudinal Tension

Answer 10

• Stretching forces applied to vocal fold tissue
• Use of CT, TA

Question 11

Vocal fold positions for various functions

Answer 11

Question 12

Laryngeal Vibration – Sound Source for Speech

Answer 12

• A single cycle of opening and closing takes approximately 1/100th second: therefore, the cycle repeats at rates in the region of 100 times per second (adult male speaker).
• This rate is too rapid for human ear to be able to discriminate each individual opening/closing of the vocal cords.
• However, we perceive variations in the overall rate of vibration as changes in the pitch of the voice.

Question 13

Laryngeal Engagement: process of adjusting the vocal mechanism so vibration can begin (and continue)

Answer 13

1) Medial Compression
2) Longitudinal Tension

Question 15

Bernoulli’s Principle

Answer 15

• Formulated in 1738 by Swiss mathematician & physicist Daniel Bernoulli
• As the speed (velocity) of a moving fluid (liquid or gas) increases, the pressure within that fluid decreases
• Total energy in a steadily flowing fluid system is a constant along the flow path. An increase in the fluid’s speed must therefore be matched by a decrease in its pressure.

Question 18

Vibration of vocal folds is primarily a passive mechanism! This includes two forces:

Answer 18

Aerodynamic Forces and Elastic Forces

Question 19

aerodymanic forces

Answer 19

• Vocal folds are “blown apart” due to Ptrach (tracheal or subglottal pressure)
• Bernoulli Effect:
• Relation between airflow velocity and changes in pressure
• Vocal folds are “sucked” toward each other

Question 20

Elastic Forces:

Answer 20

•Margins of vocal folds rebound due to tissue elasticity (elastic forces = restoring force in opposition to displacement)

Question 22

Vocal nodules

Answer 22

• Additional tissue that arises from misuse and abuse of the vocal folds
• Large portion of vocal disorders in children and adults that we will treat with voice disorders
• Can be unilateral or bilateral but are usually bilateral

Question 23

•THREE BASIC LARYGNEAL ADJUSTMENTS (phonation)

Answer 23

1. Vocal attack (adduction of vocal folds)
2. Sustained phonation (hold vocal folds in a fixed position
3. Terminate phonation (abduction)

Question 24

Types of Vocal Attack

Answer 24

1. Simultaneous vocal attack
2. Breathy vocal attack
3. Glottal attack

Question 25

Simultaneous vocal attack

Answer 25

• This is when expiration and vocal fold adduction occur simultaneously
• Used to initiate phonation
• Zany -no airflow before the word if you had airflow first would have the word -sany

Question 26

Breathy Attack

Answer 26

• Start of significant airflow before adducting the vocal folds
• Occurs frequently during running speech because airflow continues throughout the production of long strings of words
• Some of the adductions involved have to be produced with air already flowing
• Harry is my friend

Question 27

Glottal attack

Answer 27

• Adduction of the vocal folds occurs prior to the airflow much like a cough
• Used when words begin with a stressed vowel
• “Okay I want the car”
• Should have a buildup of tension and pressure for these words

Question 28

Ventricular phonation

Answer 28

• False or ventricular folds are used for voicing
• Usually an adaptive response to severe vocal fold dysfunction (growths)
• Phonation is usually heard as deep or raspy because of the thickness of the vocal folds
• False cords may hypertrophy (increase in size) which causes ventricular phonation

Question 30

Dynamic Adjustments of Laryngeal Mechanism for Changing Pitch

Answer 30

• Average rate of vocal fold vibration is referred to as one’s Modal fundamental frequency. F0 determines relative pitch of one’s voice. (Pitch is a perceptual concept – we perceive frequency of the voice as pitch).
• Modal F0
• Male ~ 120 Hz
• Female ~ 200 Hz
• Children ~ 300-400 Hz
• Normal adult: capable of producing pitch variations that range over two octaves
• Octave is a doubling of frequency. 100-200Hz is an octave difference, 500-1000Hz is also an octave difference

Question 31

Vocal register

Answer 31

•Refers to differences in modes of vibration of the vocal folds during sustained phonation:

1. Modal register
2. Glottal fry or pulse register
3. falsetto

Question 32

Modal Register

Answer 32

• Modal phonation
• Pattern of phonation used in daily conversation
• Most important for speech language pathologists
• Also the most efficient
• Vocal folds open from inferior to superior (bottom to top) and close from inferior to superior (top to bottom)

Question 33

glottal fry

Answer 33

• Second register
• Also called pulse register or Strohbass (straw bass)
• Crackly popcorn quality of the voice
• Low in pitch and sounds rough
• Secondary beat for every cycle of fundamental frequency

Question 34

Puberphonia

Answer 34

•Maintenance of the childhood pitch despite having passed the developmental stage of puberty