•Vegitative function
•Voiced/Voiceless
•5 layers of tissue
Supraglottic
Glottic
Subglottic
Aerodynamic Myoelastic Theory:
vibration of the vocal folds is the
product of air flow and pressure
through a constricted tube
interacting with the elastic
component of muscle tissue in
absence of repetitive muscular
contraction
Bernoulli Principle: given a constant
volume flow of air or fluid, at a point of
constriction there will be decrease in air
pressure perpendicular to the flow and
an increase in velocity of the flow
Phases:
Opening
Open
Closing
Closed
Sustained Phonation:
The interaction of subglottal
pressure, tissue elasticity, and
constriction as long as pressure
flow and vocal fold
approximation are maintained
One Vocal Fold Cycle
Cartilages
of the
Larynx
Structures
connected by
intrinsic
ligaments and
membranes
Cuneiform
Cartilage
Fibroelastic Membrane
Upper quadrangular
membranes
 Aryepiglottic folds
 Lower conus elasticus
 Vocal ligament

Valleculae:
a valley found
between the base
of the tongue and
epiglottis within
folds arising from
the
glossoepiglottic
ligaments
Pyriform Sinus:
valley lateral to
the vocal folds
Cover: 1,2,3
Body: 4,5
Mucosal Lining: 1,2
Vocal Ligament: 3,4
Muscle: 5
5 Layers of Tissue:
Squamous cell epithelium
1
Lamina propria
elastin fibers-random
2
elastin fibers-ap
3
collagen fibers-ap
4
Thyrovocalis muscle
5
Spaces




Aditus: entry to the larynx
from the pharynx above,
entryway to the first cavity
Vestibule: first cavity of the
larynx, between aditus and
ventricular/vestibular folds
Laryngeal ventricle: space
between the ventricular folds
and vocal folds
Glottis: space between the
vocal folds
The arytenoid
cartilages sit on the
superior surface of
the cricoid. The
cricoarytenoid joint
permits rotation,
rocking, and gliding.
Hyoid Bone: Only
bone in the body
that is not
attached to other
bone
Supra hyoid:
laryngeal
elevators
Infra hyoid:
laryngeal
depressors
Cricothyroid Joint:
contraction of the
cricothyroid muscle,
the effect is to tense
the vocal folds
Articular facet of
the arytenoid
cartilage permits
inward rocking,
ap gliding, and
rotation.
Intrinsic
and
Extrinsic
Laryngeal
Muscles
Intrinsic Laryngeal Muscles
Adductors
Innervation: Recurrent Branch of X Vagus



LCA: draws muscular process forward,
this rocks the arytenoids inward and
downward creating adduction
TA: pulls the arytenoids together
approximating VF, important in medial
compression (degree of force applied by
the vocal folds at their point of contact)
OA: pulls apex of arytenoid medially
which promotes adduction, enforces
medial compression, rocks arytenoids
down and in, aids in pulling the
epiglottis over the larynx, serves tight
adduction
Intrinsic Laryngeal Muscles
Abductor
Innervation: Recurrent Branch of X Vagus

PCA: pulls muscular process
posteriorly, abducts vocal
folds, direct antagonist to LCA
Glottal Tensors


CT: rocks the thyroid cartilage
downward (pars recta) and forward
(pars oblique) thus stretching or
tensing the vocal folds, this is the
major adjustment for pitch change
Inn. Superior Branch of X Vagus
ThyV: medial muscle of vocal folds,
tenses vocal folds in its activity as
antagonist to CT Inn. Recurrent
Branch of Vagus
Intrinsic Laryngeal Muscles
Relaxers
Innervation: Recurrent Branch of X Vagus

ThyM: may be considered part
of ThyA, lateral to TV
• Lateral fibers of TM adduct and
lengthen VF
• Medial fibers relax VF
• Sup ThyA: Some consider part of TM
- Relaxes VF
Lateral
Cricoaryteniod
Muscle
Interaryteniod
Muscles
Posterior
Cricoarytenoid
Muscles
Cricothyroid
Muscle
Thyroarytenoid
Muscles
Abduction
and
Adduction
Vocal Fold
Contraction
Movement
due to the
Cricothyroid M.
Extrinsic Laryngeal
Muscles
Supra Hyoid
Laryngeal
Elevators
Supra Hyoid Laryngeal Elevators
• Digastric: elevate the hyoid, can
pull mandible inferiorly if
infrahyoids are fixed
 Anterior: draw the hyoid up and
forward, Inn. V Trigeminal
 Posterior: draw the hyoid up
and back, Inn. V11 Facial
• Stylohyoid: elevates and retracts
hyoid bone, with anchoring of
infrahyoids could facilitate
tongue movement
Inn. V11 Facial
Supra Hyoid
Laryngeal Elevators


Mylohyoid: forms the floor or the oral
cavity, elevates hyoid and projects it
forward, elevation of the floor of the
mouth during the first stage of
deglutition, depress mandible with IH
fixed
Inn. V Trigeminal
Geniohyoid: superior to mylohyoid,
elevates hyoid, draws it forward,
depress mandible with IH fixed
Inn. XII Hypoglossal
Supra Hyoid
Laryngeal Elevators


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Hyoglossus: lingual depressor or
hyoid elevator Inn. XII hypoglossal
Genioglossus: muscle of the tongue
which will elevate the hyoid
Inn. XII Hypoglossal
Thyropharyngeus: part of inferior
constrictor m., propels food through
the pharynx, elevates larynx and
constricts pharynx, not a SH m.
Inn. ansa cervicalis arising from C1C3 spinal nerves
Extrinsic Laryngeal
Muscles
Infra Hyoid
Laryngeal Depressors
Infra Hyoid Laryngeal Depressors


Sternohyoid: depress hyoid,
lowering important following
pharyngeal stage of swallow,
with SH m. are contracted it
will fix hyoid and larynx
Inn. ansa cervicallis C1-C3
Omohyoid: two bellies scapula
to hyoid, depress hyoid and
larynx
Inn. ansa cervicalis C1 (sup)
C2 and C3 (inf)
Infra Hyoid
Laryngeal Depressors


Sternothyroid: depress thyroid
cartilage, draws larynx inferiorly
following pharyngeal stage of
swallow
Inn. spinal nerves from C1 and C2
that course in the hypoglossal nerves
Thyrohyoid: superior counterpart of
sternothyroid, either depress hyoid or
raise larynx depending on who is
fixed
Inn. spinal nerves from C1 that
course in hypoglossal nerve
Oscillation: continued vibration
Elasticity: return to original shape
after being displaced
Stiffness: strength of the forces held
within a given material that restores
it to its original shape after being
distended
Inertia: property of mass that
dictates that a body in motion tends
to stay in motion
Periodic: repeats itself in a
predictable fashion
Cycle of Vibration: moving
from one point in the
vibratory pattern to the same
point
Period: the time it takes to
pass through one cycle of
vibration
Frequency: how often something occurs,
how often a cycle of vibration repeats itself,
frequency equals 1 divided by the time it
takes for one period
f=1/T: T=1/f
Frequency is measured in Hertz (Hz) which
is the numbers of cycles per second
Vocal Fundamental Frequency


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The primary frequency of
vibration: Fo
100Hz
Harmonics (Ho) are multiples of
this Fo
200,300,400,500HZ
Formant Frequencies are vocal
tract resonances, do not relate to
the Fo or Ho
400HzF1 2600HzF2
Vocal Intensity


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Relative power or pressure of an
acoustic signal
Direct function of the amount of
pressure exerted by the sound
wave
Measured in decibles (dB)
Vegitative
Function
Cough
Throat Clearing
Swallow
Abdominal Fixation
Laryngeal Postures
Vocal Attack

Attack: the process of bringing
vocal folds together to begin
phonation
• Simultaneous vocal attack:
coordinate adduction and onset of
respiration
• Breathy Vocal Attack: starting
significant air flow before adducting
the vocal folds
• Glottal Attack: adduction of the
vocal folds occurs prior to air flow,
hard glottal attack may damage
vocal tissues
Register/Mode
•Vocal Register: differences in mode of
vibration of vocal folds

Mode of Vibration: pattern of
activity that the vocal folds
undergo during a cycle of
vibration, varies for each register

VF variation dependent on
laryngeal tension, medial
compression subglottal pressure
Registers
• Modal: the pattern of phonation
used in daily conversation
 Pressed: medial compression
is greatly increased, strident
or harsh quality, vocal abuse
 Breathy : inadaquate closure
in closed phase, inefficient
with air wastage
Registers
• Glottal Fry: different or syncopated
vibration in low frequency, rough
perceptually, low subglottal
pressure, reduced vocalis tension,
vibrating margin flaccid and thick,
strong medial compression due to
lateral portion of vocal fold is
tensed, long closed cycle
• Falcetto: elevated pitch, breathy,
vocal folds lengthen and are thin,
glottis remains open, no closed
cycle
Whispering


Not a phonatory mode
VF partially adducted and tense
• Produces turbulent air stream
• Enlarged space in cartilagenous
larynx
• Breathy vs tense whisper
Vetricle Transverse
Transverse Phase: less
consistent, opening
posterior to anterior,
closing posterior is last
Verticle and
Transverse
Phase
Relationships
During One
Glottic Cycle
Verticle Phase:opening
and closing is inferior to
superior
Frequency, Pitch, Pitch Change

Pitch
• Perceptual correlate of frequency
• Important element in speech
perception
• Change is perceived when mass of
VF and elastic elements change
• Increase by stretching and tensing
VF using cricothyroid and vocalis m.
Frequency, Pitch, Pitch Change

Optimal Pitch
• Most appropriate for an individual
• Function of mass and elasticity of
VF
• About ¼ octave above the lowest
frequency of vibration
• Function of gender and age
Frequency, Pitch, Pitch Change


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Habitual Pitch: frequency of vibration of
the vocal folds habitually used during
speech, ideally same as optimal pitch
Average Fundamental Frequency:
frequency of vibration of sustained
phonation, best determined in a
conversational sample
Pitch Range: individual Fo range
calculated as difference between lowest
and highest frequencies averages
around 2 octaves
Tension, Length, Mass of VF



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Tension increased by contraction of
the CT and TV, will increase Fo
vibration
Mass per unit length is decreased
by lengthening the VF, as mass
decreases Fo increases
Mass per unit length increases,
tension decreases and Fo decreases
Increased Fo requires increased
tension which requires increased
subglottic pressure
Intensity and Intensity Change
Intensity (SPL): physical
measure of power or pressure
ratios
Loudness: perceptual
correlate of intensity, how we
perceive pressure or power
changes
Subglottal Pressure: increased
to increase vocal intensity
Medial Compression:
increased to increase vocal
intensity
Longer Closed Phase
= Increased Intensity
= Increased VF
tension, Mass, and
Subglottal Pressure
Impedance
Measurements on EGG
Conversation Level Sustained
Vowel
Loud Sustained Vowel
Sustained Vowel at Two
Intensities
Perturbation


Frequency: cycle to cycle
variability, vocal jitter, measured
in % of differences compared to
the average period
Intensity: cycle to cycle variability,
vocal shimmer
Other Measures


Maximum Phonation Time: the
duration of phonation an individual is
capable of sustaining, indication of
phonatory plus respiratory efficiency
Diadokokinesis: alternation of
articulators (alternate motion rateAMR), coordination of the phonatory
and articulatory system
Linguistic Aspects

Suprasegmentals: parameters of
speech above the phonetic level
• Prosody: the system of stress used
to vary meaning in speech
 Pitch, intonation, loudness,
stress, duration and rhythm
Prosody
essential for naturalness


Intonation: Changes in pitch in
speech
Stress: Emphasis to syllables
or words through frequency
and intensity changes, needs
greater increase in subglottal
pressure
• Monotone: monopitch or
monoloudness affect naturalness
Declarative
Interrogative
Fo and Io changes
during a question