Chapter 3 Phonatory System Notes not to do with structures Flashcards
Vocal Fold Vibration
Vibration of the vocal folds is NOT the product of repeated adduction and abduction of the vocal folds
(Vocal Fold Vibration)
(Myoelastic - Aerodynamic Theory of Phonation):
Myoelastic, Elasticity
Returns to original shape after being displaced (Vocal folds are muscles covered by delicate membranes). This soft tissue allows them to move when sufficient force is exerted.
(Vocal Fold Vibration)
(Myoelastic - Aerodynamic Theory of Phonation):
Myoelastic
Stiffness
Strength of material that restores it to original shape
(Vocal Fold Vibration)
(Myoelastic - Aerodynamic Theory of Phonation):
Myoelastic, Inertia
a body in motion tends to stay in motion
(Vocal Fold Vibration)
(Myoelastic - Aerodynamic Theory of Phonation): Aerodynamic, Bernoulli’s Principle
There will be an increase in velocity of airflow at a point of constriction,
And a decrease in air pressure perpendicular to the flow
Laryngeal Function
Attack: adduct vocal folds to initiate phonation,
Sustain Phonation: maintain laryngeal posture, ongoing airflow maintains the vibration,
Termination: abduct vocal folds to stop phonation
(Frequency/Pitch and Amplitude/Loudness):
Frequency
Rate of vibration of an object,
Measured in cycles per second(Hertz -Hz)
(Frequency/Pitch and Amplitude/Loudness):
Pitch
Perception of sound’s frequency,
Vibration rate related to vocal fold thickness (mass), length, and elasticity (tension)
(Frequency/Pitch and Amplitude/Loudness):
Pitch, Higher Pitch
Faster the vibration (the higher the frequency) the higher the sounds will be perceived,
Contraction of cricothyroid muscles, (Lengthens vocal folds and thins medial edge)
(Frequency/Pitch and Amplitude/Loudness):
Pitch, Lower Pitch
Slower the vibration (the lower the frequency) the lower the sound will be perceived,
Contraction of thyromuscularis,
Brings thyroid cartilage and arytenoids closer together,
Shortens vocal fold length, making them more massive and less tense
(Frequency/Pitch and Amplitude/Loudness):
Amplitude
Amount of displacement of an object from its rest position,
Measured in decibels (dB)
(Frequency/Pitch and Amplitude/Loudness):
Loudness
Perception of the sound’s amplitude, Increase Loudness:
The greater the amplitude the louder is the sound that is heard and vice versa,
Increase medial compression of vocal folds, (Vocal folds press together more tightly), (Vocal folds press together for a longer period of time)
(Voice Quality):
Normal Voice Quality, Maximum frequency range
The voice is flexible in pitch during conversation
(Voice Quality):
Normal Voice Quality, Minimum - maximum amplitude
The voice is able to vary loudness
(Voice Quality):
Normal Voice Quality, Maximum phonation time
Measured by the longest period of time that an individual can sustain a vowel on one breath,
Coordinated air flow with vocal fold adduction,
Adults: 15 -25 seconds
Children: at least 10
(Voice Quality):
Normal Voice Quality, Minimal additive noise
Minimal breathiness or roughness
(Abnormal Voice Qualities): Dysphonia
Generic term for any voice that sounds deviant in terms of quality, pitch, and or loudness
(Abnormal Voice Qualities): Dysphonia, Breathiness
Vocal folds don’t close completely during each vibratory cycle,
Air leakage at the glottis creates a friction noise,
Breathy noise is measured at the higher frequencies
(Abnormal Voice Qualities): Dysphonia, Rough/Hoarse Voice
Excessive vocal fold closure during phonation,
Vocal folds vibrate in a less periodic cycle,
Rough/Hoarse noise is measured at the lower frequencies
(Acoustic Analysis): Praat, Advantages
Easily accessible,
Inexpensive,
Safe and non-invasive,
Provides quantifiable data
(Acoustic Analysis): Praat, Disadvantages
Different calculation algorithms for different programs,
Not useful for severely dysphonic voices,
Validity and reliability issues (placement and quality of microphone, background noise, acoustics in the room)
(Acoustic Analysis): Perturbation Measurement, Jitter
Frequency perturbation (timing variability between cycles of vibration),
Normal jitter values: 0.2% to 1%
(Acoustic Analysis): Perturbation Measurement, Shimmer
Amplitude perturbation (amplitude variability between cycles),
Normal shimmer values: below 0.5 dB
(Acoustic Analysis): Noise Measures, Harmonic to noise ratio
Measures the amount of additive noise in the voice,
Lower than normal harmonic to noise ratio: suspect problems with vocal fold vibration/adduction
(Vocal Fold Disorders): Laryngitis
Inflammation of the vocal folds,
Caused by excessive use of the voice, infections, inhaled irritants, or reflux
(Vocal Fold Disorders): Vocal nodules
Noncancerous growths on the vocal cords, similar to a callus,
Most often caused by vocal abuse
(Vocal Fold Disorders): Vocal polyps
Soft noncancerous growth, similar to a blister
(Vocal Fold Disorders): Vocal fold paralysis
One or both vocal folds doesn’t open or close,
Caused by injury, problems in surgery, stroke, cancer, neurological disorders
(Facilitative and Aversive Activities of the Vocal Folds): Whisper, Relaxed whisper
Less stressful to vocal folds,
More open and softer
(Facilitative and Aversive Activities of the Vocal Folds): Whisper, Forced whisper
Strong, funneled air stream,
Stiffened folds,
Turbulence just above glottis
(Facilitative and Aversive Activities of the Vocal Folds): Yawning
Facilitates relaxation of vocal tract musculature
(Facilitative and Aversive Activities of the Vocal Folds): Coughing
Airway protection,
Encourage adduction of vocal folds,
Prolonged cough abusive to vocal folds
(Facilitative and Aversive Activities of the Vocal Folds): Throat Clearing
(vocal folds grate on each other)
Can help remove irritants,
Entire larynx goes into stressful movements, (Encourage very soft and breathy clearing), (Loud or frequent -abusive to vocal folds)
(Facilitative and Aversive Activities of the Vocal Folds): Throat Clearing
(vocal folds grate on each other)
Can help remove irritants,
Entire larynx goes into stressful movements, (Encourage very soft and breathy clearing), (Loud or frequent -abusive to vocal folds)
(Facilitative and Aversive Activities of the Vocal Folds): Laughing
Laryngeal musculature are reflexively relaxed,
Can help generate efficient vocal physiology in voice therapy,
Can cause excessive laryngeal pressure and stress if done too loudly or excessively
(Facilitative and Aversive Activities of the Vocal Folds): Crying, Open or relaxed cry
Enriched resonance between the vocal folds and the supraglottic resonating spaces
(Facilitative and Aversive Activities of the Vocal Folds): Crying, Tight, loud, or excessive crying
Laryngeal and supraglottic musculature are tensed