Download Slide Set 1: Anatomy and Physiology of Voice Production

SPPA 6400 Voice Disorders
Stephen M. Tasko
SPPA 6400 Voice
Disorders: Tasko
Some Questions
• What is a voice disorder?
• Is a voice disorder different form a speech
disorder?
• Is a voice disorder different from a resonance
disorder?
• How common are voice disorders?
• Who gets a voice disorder?
• Why might someone have a voice disorder?
• How do you know if someone has a voice
disorder?
SPPA 6400 Voice
Disorders: Tasko
Application of Physics and Biology
to Voice Production
• (Bio)Mechanics
• Aerodynamics
– Dynamics/statics vs.
– Volume, pressure and
Kinematics
volume velocity (flow)
characteristics of air
– Active (muscular) vs. Passive
molecules
system properties
• Acoustics
– Tissue properties such as
stiffness, elasticity
– sound pressure wave as
a consequence of
• Neuromuscular Physiology
biomechanical and
– Sensorimotor function
aerodynamic
– Motor “Control”
interactions
SPPA 6400 Voice
Disorders: Tasko
Voice Production Within an
Integration of Subsystems
• Respiration
• Phonation
• Resonation
Colton, Casper & Leonard (2011)
SPPA 6400 Voice
Disorders: Tasko
Voice Production Within Source Filter
Theory of Speech Production
Source
(Phonation)
Filter
(Resonator)
Radiated Sound
(What We Hear)
Input Spectrum
Frequency Response
Curve
Output Spectrum
SPPA 6400 Voice
Disorders: Tasko
Voice Production:
Role of Respiration
•
Respiratory Aerodynamics
– Modify thoracic volume which
– Alters alveolar (lung) pressure, which
– Results in respiratory airflow
– Resisting this airflow using the
laryngeal valve allows the
establishment of a driving pressure for
vocal fold oscillation (or other sound
generation)
SPPA 6400 Voice
Disorders: Tasko
Voice Production:
Role of Respiration
•
Respiratory Biomechanics
– Passive System Properties
• Elastic properties
• Environmental forces (gravity)
– Active System Properties
• Principally muscle activity
(inspiratory or expiratory)
• Under nervous system control
(automatic or voluntary)
• Must account for passive
properties
SPPA 6400 Voice
Disorders: Tasko
Voice Production:
Role of Respiration
Lung Volume Above
Resting Lung Volume
Resting Lung Volume
Lung Volume Below
Resting Lung Volume
SPPA 6400 Voice
Disorders: Tasko
Voice Production: Role of Larynx
Laryngeal Cartilages
SPPA 6400 Voice
Disorders: Tasko
Voice Production: Role of Larynx
Ligaments, membranes and joints
SPPA 6400 Voice
Disorders: Tasko
Cricothyroid Joint
Actions
• Pitch rotation
• Horizontal translation
SPPA 6400 Voice
Disorders: Tasko
Cricoarytenoid Joint
Action
• Pitch and roll – rocking
• Translation – sliding or
gliding
SPPA 6400 Voice
Disorders: Tasko
Conus Elasticus & Vocal
Ligament
From Gilroy et al. (2008)
SPPA 6400 Voice
Disorders: Tasko
Laryngoscopic view:
Key Structures
• True vocal fold
– Cartilaginous portion
– Membranous portion
• False vocal fold
• Glottis
– Anterior commissure
– Posterior commissure
•
•
•
•
•
•
•
•
Epiglottis
Arytenoid c.
Interarytenoid region
Aryepiglottic fold
Valleculae
Pyriform fossae
Posterior pharyngeal wall
Opening to esophagus
SPPA 6400 Voice
Disorders: Tasko
Laryngoscopic view:
Key Structures
• True vocal fold
– Cartilaginous portion
– Membranous portion
• False vocal fold
• Glottis
– Anterior commissure
– Posterior commissure
•
•
•
•
•
•
•
•
Epiglottis
Arytenoid c.
Interarytenoid region
Aryepiglottic fold
Valleculae
Pyriform fossae
Posterior pharyngeal wall
Opening to esophagus
SPPA 6400 Voice
Disorders: Tasko
Interior view of larynx
Laryngeal Anatomy: The
muscles
1. Intrinsic muscles
•
Both origin and insertion are within the larynx
2. Supplemental and Extrinsic muscles
•
•
Extrinsic: An origin or insertion is within the larynx
Supplemental: No origin/insertion within the larynx, but
affects the location of larynx in the neck
SPPA 6400 Voice
Disorders: Tasko
Intrinsic Laryngeal muscles
Key Actions
Position
• Adduct
• Abduct
Tension
• Tense
• Slacken
Length
• Lengthen
• Shorten
ADDUCTION
ABDUCTION
SPPA 6400 Voice
Disorders: Tasko
Lateral cricoarytenoid (LCA)
Origin:
Superior edge of
lateral border of cricoid
cartilage
Insertion:
muscular process of
arytenoid
Action: adducts VF
Motor Supply: CN X
(recurrent laryngeal nerve)
Lateral cricoarytenoid (LCA) Action
Posterior cricoarytenoid (PCA)
Origin:
Posterior (dorsal) surface
of cricoid cartilage
Insertion:
muscular process of
arytenoid
Action: abducts VF
Motor Supply: CN X
(recurrent laryngeal nerve)
Posterior cricoarytenoid (PCA)
Posterior cricoarytenoid (PCA)
Action
Thyroarytenoid (TA)
Often considered to have 2 parts
•
Vocalis
•
Thyromuscularis
Origin:
Internal surface of the thyroid
angle
Insertion:
Vocal and muscular process of
arytenoid
Action: shorten & adducts VF
Motor Supply: CN X
(recurrent laryngeal nerve)
Thyroarytenoid (TA)
Thyroarytenoid (TA) Action
From Netter
(Inter)arytenoid (IA)
Often considered to have 2 fiber types
•
Oblique
•
Transverse
Origin:
Posterior (dorsal) surface of
arytenoid surface
Insertion:
Posterior (dorsal) surface of
opposite arytenoid
Action: adducts VF
Motor Supply: CN X
(recurrent laryngeal nerve)
Interarytenoid (IA) Action
From Netter
Cricothyroid (CT)
Often considered to have 2 fiber types
•
Oblique
•
Vertical
Origin:
ventral and lateral surfaces of
arch of cricoid cartilage
Insertion:
Caudal border of the thyroid
cartilage and anterior surface of
inferior horn
Action: lengthens and tenses VF
Motor Supply: CN X
(external branch of superior laryngeal
nerve)
Cricothyroid (CT) Action
SPPA 2050
Speeech Anatomy
From Netter
30
Summary of Key Actions
SPPA 6400 Voice
Disorders: Tasko
Nerve supply to larynx
• Cranial Nerve X (Vagus N.)
– motor supply to all intrinsic muscles
– sensory for larynx
– 2 branches important for larynx
• Superior laryngeal n.
– Internal branch
» sensory supply
– External branch
» cricothyroid m.
• Recurrent laryngeal n.
– all other intrinsic muscles
SPPA 6400 Voice
Disorders: Tasko
Thyroid Gland
Supplemental & Extrinsic laryngeal muscles
• “Suspends” larynx in the neck
• may elevate or depress hyo-laryngeal complex
• Suprahyoid muscles: muscles that attach to
sites rostral to the hyoid bone
• Infrahyoid (aka ‘strap’) muscles: muscles that
attach to sites caudal to the hyoid bone
SPPA 6400 Voice
Disorders: Tasko
Suprahyoid muscles
SPPA 6400 Voice
Disorders: Tasko
Infrahyoid muscles
SPPA 6400 Voice
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Vocal Fold Histology
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Vocal Fold Histology
Epithelium
Basement Membrane Zone (BMZ)
connective tissue
superficial layer
tissue loosely connected to the other layers
intermediate layer
Lamina
propria
elastic fibers (stretchy)
Vocal ligament
deep layer
collagen fibers (not stretchy)
muscle (TA)
SPPA 6400 Voice
Disorders: Tasko
Myoelastic Aerodynamic Theory of
Phonation
Necessary and Sufficient Conditions
• Vocal Folds are adducted (Adduction)
• Vocal Folds are tensed (Longitudinal Tension)
• Presence of Aerodynamic pressures (driving pressure)
Vocal Fold Oscillation
•VF adducted & tensed → myoelastic pressure (Pme )
•Glottis is closed
•subglottal air pressure (Psg) ↑
•Psg ~ 8-10 cm H20, Psg > Pme
•L and R VFs begin to separate (starting at bottom)
•Transglottal airflow (Utg) = 0
As bottom part of fold separates, top part follows is
“pulled” along
glottis begins to open
Psg > Patm therefore Utg > 0
Vocal Fold Oscillation
With the glottis now open and glottal airflow (Utg)
high, intraglottal pressure (Pig) drops due to
changing shape of the space between the glottis
Plus “other” aerodynamic effects
Pig < Pme
Vocal fold returns to midline
Utg = 0
Pattern repeats 100-200 times a second
Vocal Fold Oscillation
SPPA 6400 Voice
Disorders: Tasko
Complexity of vocal fold vibration
Vertical phase difference
Longitudinal phase difference
The Glottal Cycle
Phonation is actually quasi-periodic
• Complex Periodic
– vocal fold oscillation
• Aperiodic
– Broad frequency noise embedded in signal
– Non-periodic vocal fold oscillation
– Asymmetry of vocal fold oscillation
– Air turbulence
• Voicing vs. whispering
Instantaneous
sound pressure
Sound pressure wave
Time
Characterizing Vocal Fold Vibration
• Fundamental Frequency
• Amplitude
• Waveform Features
SPPA 6400 Voice
Disorders: Tasko
Fundamental Frequency (F0)
What factors dictate the vibratory frequency of the vocal folds?
• Anatomical factors
Males ↑ VF mass and length = ↓ Fo
Females ↓ VF mass and length = ↑ Fo
• Subglottal pressure adjustment – show example
↑ Psg = ↑ Fo
• Laryngeal and vocal fold adjustments
↑ CT activity = ↑ Fo
TA activity = ↑ Fo or ↓ Fo
• Extralaryngeal adjustments
↑ height of larynx = ↑ Fo
Amplitude
• Subglottal pressure adjustment
↑ Psg = ↑ sound pressure
• Laryngeal and vocal fold adjustments
↑ medial compression = ↑ sound pressure
• Supralaryngeal adjustments
– Optimizing sound radiation from vocal tract
Waveform Features
For example,
• Waveform “shape”
• Periodic vs. aperiodic energy components
Waveform Shape: Spectral Tilt
Waveform Shape: Spectral Tilt
Pressed
Breathy
Waveform Shape:
Periodic vs. Aperiodic
SPPA 6400 Voice
Disorders: Tasko
Voice Production:
Role of Resonation
From Titze (1994)