1. Physiology of Phonation
Ch. 5

2. Nonspeech Laryngeal function
Protection is the most important role
Prohibits entry of foreign objects into the lungs
Cough-
response by the tissues of the respiratory passageway to an irritant or foreign object
Mediated by Vagus nerve
Deep inhalation-widely abducted vocal folds, followed by tensing and tight adduction of the vocal folds and elevation of the larynx
Arytenoids are rocked for adduction and directed downward, providing more force
cough reflex

3. Nonspeech Laryngeal Function
Throat Clearing
Not as violent as a full cough
Build pressure in the subglottal region and clamp the vocal folds shut to restrain the pressure
Places vocal folds under a great deal of strain
Involve the muscles of adduction;
lateral cricoarytenoid,
arytenoids and
thyrovocalis.

4. Nonspeech Laryngeal Function
Abdominal fixation
Capturing air within the thorax to provide the muscles with a structure to push/pull
Similar to a cough
Take in a large breath, tight adduction of the vocal folds
Thorax becomes a rigid frame
Some air may escape through the adducted vocal folds and you may “grunt” when lifting something heavy

5. Nonspeech Laryngeal Function
Breathing
Normal breathing requires the vocal folds to be abducted
During forced exhalation (like when exercising)- the need for air causes you to increase the abduction of the vocal folds
deep breathing during first couple of seconds of video

6. Laryngeal Function for Speech
Bernoulli Effect
This explains how we maintain phonation
Need a constant volume flow of air
Vocal folds become a source of turbulence in the vocal tract
Effects of constricting a tube during air flow
As it flows through the constriction- the rate (velocity) of flow increases, however, the pressure decreases
Vibration of the vocal folds is the product of airflow interacting with the tissue in the absence of repetitive muscular constriction
start at 1:43

7. Bernoulli Effect

8. Laryngeal Function for Speech
Attack
Process of bringing vocal folds together to begin phonation, requires muscular action
Simultaneous vocal attack-coordinate adduction and onset of respiration so that they occur simultaneously (i.e. say the word “zany”- you start the flow of air before voicing)

9. Laryngeal Function for Speech
Breathy vocal attack-starting significant airflow before adducting the vocal folds (i.e. running speech “Harry is my friend.” you can feel the air flow past your lips
Glottal attack- adduction of the vocal folds occurs prior to the airflow, much like a cough (i.e. bring vocal folds together like you are going to cough- and then say /a/, or say “okay, I want the car.”
Hard Glottal attack- an attack is misused- too much force- causes damage to vocal folds

10. Laryngeal Function for Speech
Termination
When phonation stops the vocal folds abduct
We pull vocal folds out of the airstream far enough to reduce the turbulence, using muscular action- the vocal folds stop vibrating
It occurs many times during running speech

11. Adduction Is constant in all types of phonation and attack
The arytenoid cartilages move in three dimensions: rotating, rocking, and gliding
Primary movement for adduction is inward rocking
Combined forces of the cricothyroid and posterior cricoarytenoid cause the entire glottis to lengthen

12. Vocal Fold Nodules
Aggregates of tissue arising from abuse- Unilateral or Bilateral
Continued abuse results in the formation of a protective layer of epithelium that is callous-like
Usually on the juncture of the anterior and middle thirds of the vocal folds- greatest impact during phonation
Yelling, screaming, cheerleading, singing
Laryngitis-inflammation of the larynx, hoarseness ad possible loss of voice (aphonia).
Swelling of the vocal fold tissue with a breathy voice
Can be caused by vocal hyperfunction (over adduction of the vocal folds)
After a thrilling football game

13. Vocal Nodules

14. Laryngitis
Laryngitis-inflammation of the larynx, hoarseness ad possible loss of voice (aphonia).
Swelling of the vocal fold tissue with a breathy voice
Can be caused by vocal hyperfunction (over adduction of the vocal folds)
After a thrilling football game

15. Sustained Phonation
Vocal attack and termination requires muscular action
Sustained phonation requires maintenance of a laryngeal posture through sustained contraction of musculature.
Vocal folds are held in place- it is not the product of repeated adduction and abduction- muscle spindles embedded within the thyrovocalis and thyromuscularis serve the function in holding sustained posture

16. Vocal Register
Mode of vibration- pattern of activity that the vocal folds undergo during a cycle of vibration
Three registers-differences in the mode of vibration of vocal folds
Modal register
Glottal fry or pulse register
Falsetto

17. Modal Register Pattern of phonation used in daily conversation
Vertical mode of phonation is when the vocal folds open from bottom to top and close from bottom to top- like a wave
Primary frequency of vibration- vocal fundamental frequency
Anterior-Posterior dimension of phonation- vocal folds open from posterior to anterior but closure is made by contact at the medial edge

18. Glottal Fry Also called “fry, pulse, and straw bass” voice
Crackly, popcorn quality of voice
Low in pitch, sounds rough
Frequencies as low as 30 Hz to Hz
Low subglottal pressure and tension of the vocalis is reduced
Vibrating margin is flaccid and thick
Lateral portion of the vocal folds is tensed – strong medial compression with short, thick, vocal folds and low subglottal pressure
Syncopated mode of vibration- a secondary beat for every cycle- the vocal folds don’t just vibrate slower, but differently

19. Falsetto Vibratory pattern that varies from modal production
Vocal folds lengthen and become thin and “reed like”
Vibrate along the tensed, bowed margins
Make contact only briefly and the degree of movement is reduced
Thin, high- pitched voice
Whistle register- above falsetto- product of turbulence on the edge of the vocal fold- frequencies as high as 2500 Hz

20. Pressed and Breathy Phonation
Pressed phonation
Medial compression is greatly increased
Increase in stridency or harsh quality
Increase in abuse to the voice
Stronger, louder phonation
Forceful adduction often results in damage to vocal fold tissue

21. Pressed and Breathy Phonation
Breathy voice
Vocal folds are inadequately approximated
Vibrating margins permit excessive airflow between then
Inefficient and causes air wastage
May signal the presence of vocal nodules, polyps or laryngeal cancer

22. Whispering Not a phonatory mode No vibration of the vocal folds
Vocal folds are partially adducted and tensed to develop turbulence in the airstream
The turbulence is the noise you use to make speech
Arytenoid cartilages are rotated slightly in but are separated posteriorly
No voicing, however, it is strenuous and can cause vocal fatigue

23. Intensity
Relative power or pressure of an acoustic signal, measured in decibels (dB)
Amount of pressure exerted by the sound wave

24. Ventricular Phonation
False or ventricular vocal folds are technically unable to vibrate for voice
In some instances- clients may use ventricular phonation as an adaptive response to severe vocal fold dysfunction
Forces the lateral superior walls close together
Phonation is deep, raspy

25. Sustained and Maximum Phonation
Sustain /ah/
Sustain /s/
Sustain /z/

26. Pitch Psychological correlate of frequency
As frequency increases, pitch increases
Vocal folds tend to vibrate at the same frequency when mass and elastic elements remain constant
Frequency of vibration changes when mass and elastic elements change

27. Optimal Pitch
Vocal fold vibration that is most appropriate for an individual
Most efficient for a pair of vocal folds
Considered 1/4th octave above the lowest frequency
Can be estimated from a throat clearing
Varies from gender and age
Females average 212 Hz, Males 132 Hz

28. Habitual Pitch
Frequency of vibration of vocal folds that is habitually used during speech
Ideally this would be the same as optimal pitch
The choice to use an abnormally higher or lower fundamental frequency is often not a conscious decision
When forcing vocal folds to extremes of their range of ability- greater effort and physical fatigue

29. Average Fundamental Frequency
Frequency of vibration of sustained phonation or conversational speech
Reflects habitual pitch over a longer averaging period
Use conversational speech or reading tasks to accurately reflect
Pitch range- difference between the highest and lowest frequencies- capable of approximately two octaves

30. Pitch Changing Stretching and tensing the vocal folds
Use the cricothyroid and thyrovocalis muscles
Changeable elements are tension, length and mass through elongation
Cricothyroid- thyroid tilts down, lengthening the vocal folds and increasing fundamental frequency
Thyrovocalis- pulls cricoid and thyroid closer

31. Pitch changing
Posterior cricoarytenoid- has muscle spindles that moitor and maintain tonic muscle length
Cricothyroid makes the gross adjustment, Thyrovocalis fine tunes the adjustment
Increased subglottal pressure is a response to the increased tension
Mass is rearranged by lengthening or shortening
Relaxing the vocal folds- contraction of the thyromuscularis- folds are relaxed and shortened becoming more massive and less tense

32. Intensity Loudness is the pscyhological correlate of intensity
Physical measure of power or pressure
Increase the vigor with which the vocal folds open and close
Subglottal pressure and flow provide the energy
Increase subglottal pressure to increase vocal intensity

33. Changing Intensity Increased medial compression of vocal folds
Vocal folds are tightly compressed
Takes more force to blow them open
They close more rapidly
Stay closed because they are tightly compressed
Intensity and Frequency are controlled independently, however, it is difficult to increase intensity without increasing pitch unless you are trained. Intensity and frequency increasing together is a natural process

34. Clinical Considerations
Perturbation (jitter)
Measures cycle-by-cycle variability in phonation- measures perception of “hoarseness”
Increased mass (vocal nodules) will increase perturbation
Neuromotor dysfunction will increase perturbation
Provides another measure of how the phonatory system is functioning

35. Clinical Considerations
Prosody
System of stress used to vary the meaning in speech
Elements include pitch, intonation, loudness, stress, duration and rhythmn
Provides information concerning emotion and intent and can provide clearer meaning
Diadochokinesis
Alternation of articulators (puh tuh kuh)
Assesses the coordination between the phonatory and articulatory systems