Physiology of Phonation Ch. 5 Flashcards
What is the most important role of the larynx?
Protective function. Prevents entrance of foreign objects into lungs, by coughing, throat clearing, abdominal fixation (impounds air in thorax to stabilize torso.)
What is the process of vibration? (acoustics)
Elasticity: property of material causing it to return to original shape after displacement.
Stiffness: Strength of force within a material to return to it’s original shape after distention.
Inertia: a body in motion tends to stay in motion.
Periodic Waveform
Repeats itself in a predictable fashion.
Cycle
One point in a vibratory pattern to the same point again.
Period
Time to complete one cycle of vibration.
Frequency
How often something occurs; cycles per sec.
Hertz (Hz)
Cycle per second (perceived as Pitch)
Intensity
Increased amplitude of waveform
Sound Pressure formula
P=F/A
Amplitude of wave
Degree to which waveform goes beyond x axis
Decible
dB (loudness)
Sound Level Meter
Measures intensity of sound pressure coming from a source.
Fundamental Frequency
Frequency of vibration of Vocal folds
Vocal Jitter
Cycle by cycle differences in vocal fold vibration.
Vocal Shimmer
Cycle by cycle differences in intensity.
Phonogram
Interaction between intensity and frequency
Pneumotachograph
airflow in a face mask
Fiberendoscopy
View VF from above via nasal cavity measures swallowing.
Subglottal pressure
measured via hypodermic needle through the cricothyroid or estimated by intraoral pressure when the vocal folds are open.
Electroglottograph
Electrodes on the neck- measures impedance which corresponds with vocal fold contact.
What is the laryngeal function for speech?
Phonation=voicing
Vibrating Vocal folds w/in larynx.
Phonation maintained by Bernoulli Effect and tissue elasticity.
Bernoulli Effect
Dictates that a constant volume flow of air or fluid, at a point of constriction there will be a decrease in air pressure perpendicular to the flow and increase in velocity of flow. “lower pressure higher speed”
Bernoulli Effect Vocal folds
phonation is the product of vibrating vocal folds w/in larynx.Vocal folds vibrate as air passes through them.
Phonation is maintained by the Bernoulli effect and tissue elasticity
Attack
beginning of phonation
Adduction
Process of bringing vocal folds together (adduction)
Simultaneous Vocal Attack
adduction and onset of respiration at the same time
Breathy Vocal Attack
Attack-start significant airflow before adducting the vocal folds
Glottal Attack
adduction of the vocal folds prior to the airflow- if hard may damage the vocal mechanism
Arytenoid Cartilages can move in three dimensions
Rotating
Rocking
Gliding
Abduction of vocal folds
Move the vocal folds apart
Terminates phonation frequently when speaking
Accommodates voiced and voiceless speech sounds
Sustained Phonation
Adduction and abduction for speech. Depends on, Maintenance of pressure
Flow
Vocal fold approximation
vocal registers
Modal Register
Glottal (fry/pulse) Register
Falsetto
Modal Register
Phonation used in daily conversation
Glottal (fry/pulse) Register
Crackly voice
Vocalis is tense
Falsetto
Highest register
Vocal sounds higher than normal range
Puberphonia
Pressed
Medial compression is greatly increased
Breathy
Inadequate vocal fold approximation with excessive airflow between vocal folds in closed phase
PITCH
Psychological correlate of frequency
Important in speech perception
FREQUENCY
Number of cycles of vibration per second
Pitch ⬆, Frequency ⬆
Pitch ⬇, Frequency ⬇
Optimal Pitch
Frequency of vibration that is most efficient for a pair of vocal cords
Female average= 212 Hz
Male average= 132 Hz
Habitual Pitch
Frequency habitually used by a person
Pitch Range
Fundamental frequency for an individual
Difference between lowest and highest frequencies
Stretching and tensing vocal folds
Tension, length, mass
Pitch-Changing Mechanism
Comes from stretching and tensing vocal folds
Uses cricothyroid and thyrovocalis muscles
Depends on changeable elements of vocal folds
Opening stage
Vocal folds are opening up
Closing stage
Vocal folds are returning to point of approximation
Closed stage
No air is escaping between the vocal folds
Diadochokinesis
alternation of articulators producing single or multiple syllables per second
Elements of prosody
Pitch
Stress
Intonation-change in pitch
Duration
Loudness
Rhythm
Myoelastic-aerodynamic Theory
Myoelastic component of muscle (myo + muscle) and the soft tissues of the larynx
Aerodynamic component is airflow and compression through the compressed tube
Titze Model
The loosely bound masses associated with the membranous cover of the vocal folds
The body of the vocal folds
