Phonatory System: Speech Physiology (EXAM 2) Flashcards
Speech functions of larynx
Vibration primer
Glottal configuration
Glottal cycle
Phonation threshold pressure (PTP)
Pitch and Fundamental frequency
Pitch control
Loudness
Vibration Primer
Phonation primer
Vibrations generated by air pressure build up = phonation
HOW?: Aerodynamical event to acoustic event
VF obstruct exhalation air stream
Builds up PTP
Sets VF into motion if reach PTP
Results in rapid changes in air pressure
Results in acoustic event
Glottal Configuration
Space between VF varies according to the activity
Types:
Large glottis
Medium glottis
Small glottis
Small at back glottis
No glottis
Quiet Breathing
Medium glottis for both inhalation and exhalation (no speech)
Minimal muscle activity of posterior cricoarytenoid (abductor)
Forced Inhalation
Large glottis for both inhalation and exhalation
Great posterior cricoarytenoid (abductor) action
Voiceless sounds
Medium glottis
VF abducted for brief, unobstructed airflow
Airflow altered in oral cavity results in voiceless sounds
Voiced sounds
No-to-minimal glottis
VF adducted for voiced sound
Obstructs airflow momentarily in running speech, leading to more vibration of VF
Results in voiced sounds
Whisper
Narrow/small glottis with opening at back
Partly adducted VF with airflow resistance resulting in turbulence but no phonation
Just audible hissing sound
Muscles: lateral cricoarytenoids ONLY
Breath holding
No glottis
VF fully adducted
all 3 adductor muscles
results in complete trapping of inhaled air in lower respiratory tract
Glottal cycle
2 stages:
Prephonation
Phonation
Prephonation
As exhalation phase about to begin, VF adducted by adductor trio and glottis is closed/almost closed
Phonation
4 phases:
1. Closed
2. Opening
3. Closing
4. Closed
- Closed phase
VF adducted and glottis closed (prephonation)
Exhaled airflow is blocked, more alveolar/tracheal pressure build up
(1)
- Opening phase
Alveolar pressure reaches PTP
Forces VF apart whilst adducted
Glottis opens from BOTTOM to TOP
Exhaled airflow resumes into oral cavity
(2-5) (4)
- Closing phase
Air flow continues
Alveolar pressure decreases as air leaves trachea
Allows VF to rebound (elasticity)
Glottis narrows
Closes from BOTTOM to TOP
(6-9) (9)
- Closed phase
Glottis closes and cycle repeats
1 complete glottal cycle describes 1 VF vibration
10
Medial compression
Muscular force with which VF adducted or pressed together at midline by adductor muscles
What does glottal cycle achieve?
Changes the constant pressure of free airflow into alternating air pressure with obstructed air flow
Sound compression and rarefaction (Compression when open, rarefaction when closed)
Creates acoustic event of sound
Phonation threshold pressure
Minimal alveolar pressure needed to start glottal cycle, Minimum Pressure required: 3cmH20
Dependent on how LOUD you speak
3cmH20: Soft
7cmH20: Conversational
11cmH20: LOUD
Not very difficult to achieve, imagine blowing bubble in water at 3cm mark
What is vocal pitch?
Perceptual event related to glottal vibrations/second (GCPS)
More gcps= higher pitch
Less gcps= lower pitch
What is fundamental frequency?
Average number of glottal cycles per second for male/female
Adult male: 125-120 Hz
Adult female: 225 Hz
How does Fundamental frequency change over lifespan?
Females:
7: 281Hz
20-29: 224Hz
80-94: 200Hz
Males:
7: 294Hz
20-29: 120Hz
80-89: 146Hz
1st ten years of life for fundamental frequency
Relatively high for both M/F
Any drops related to change in VF length and thickness with little difference between male and female
Puberty and fundamental frequency
Males: Dramatic drop due to VF being longer and THICKER
Females: Drops somewhat for same reason
After age 60 and fundamental frequnecy
Male: Increases due to VF thinning
Female: decreases due to VF thickening
What causes lower pitch?
Longer (naturally) VF and thicker VF (But mostly thicker)
Why do adult males have longer/thicker VF?
Longer: Thyroid prominence more apparent, greater angle, longer VF (natural, not stretched)
Thicker: Hormone
Pitch control
Changes glottal cycle duration (period)
Leads to changes of number of gcps (frequency)
changes pitch
Compliance
Willingness to yield to aerodynamic forces
Elastic properties of VF affects response
More elastic= more resistant= less compliant
Less elastic=less resistant= more compliant
How do you change duration of glottal cycle?
Change length of VF
Change tension of VF
Raise/lower larynx
Change VF Length: Lengthening VF
Appearance: Long, thin, stiff
Muscle: Cricothyroid contracts
Increase VF length
Increase VF tension
Decrease VF Compliance
Less duration of gcps
more gcps
Higher pitch
Change VF Length: Shortening VF
Appearance: short, thick, lax
Muscle: Cricothyroid relax, tense thyroarytenoid (slightly)
Decreases VF length
Decrease VF tension
Increase VF compliance
Increase duration of gcps
Decrease gcps
lower pitch
Change VF Tension
- Change VF length
- Tensor Muscles (Thyroarytenoids)
Extra High Pitch:
After lengthening VF
Tense thyroarytenoids
Less compliant
Less duration
more gcps
higher pitch
Extra low pitch:
After shortening VF
Relax thyroarytenoids
More compliant
more duration
less gcps
lower pitch
Analogy: Big belly and tight six pack
Short, thick, lax: Big belly
More compliant
less duration (in closed phase longer)
less gcps
Long, thin, stiff: tight six pack
Less compliant
more duration (hardly in closed phase)
more gcps
Change height of larynx
Using extrinsic muscles to change filter characteristics
Longer vocal tract: lower pitch resonant
Shorter vocal tract: higher pitch resonant
Suprahyoid: raise/higher pitch
Infrahyoid: lower/lower pitch
Loudness
Perceptual event related to vocal intensity
Amplitude of sound: dBSPL
Corresponds to alveolar pressure
How to change loudness?
Changing aerodynamic forces
-change volume of air
-change air pressure
Changing muscular forces
-change medial compression
without medial compression, cannot accomplish true alveolar pressure build up
Changing medial compression
Adductors
If more medial compression: firm glottal closure, more resistant to airflow, more ptp
If less medial compression: relaxed glottal closure, less resistant to airflow, less ptp
Increasing loudness
Change aerodynamic forces
-increase volume
-increase pressure
Change muscular forces
-increase medial compression, firm glottal closure, more force needed to separate folds, can hold in more pressure
As a result: exhaled air velocity faster, results in VF closing with greater force
Concerns: Vocal nodules, temporary damage to VF
Hoarseness
Decreasing loudness
Change aerodynamic forces:
-decrease volume
-decrease pressure
Change muscular forces
-less medial compression, relaxed glottal closure, less alveolar pressure, less force needed to separate folds
As a result: exhaled airstream velocity decreases, glottis doesn’t slam, soft/convo levels of loudness for long periods of time less harm
drink water
Whispering
Change aerodynamic forces
-maintain steady airflow
change muscular forces
-adjust VF to whisper triangle with lateral cricoarytenoids ONLY
leads to: turbulent and audible hissing sound
