Airflow and Phonation
Two Phases of Phonation
Prephonation Phase; Attack Phase
Cricoid Cartilage
Quadrate Lamina Arch (anterior, shorter) Articular facets (arytenoid) Articular facets (thyroid)
Quality of our Voice
Relationship between the frequencies of a complex tone and their amplitudes; Hang out between 0 and 8000 Hz
Quiet Breathing Glottal Shape
The glottis is open but not to the greatest extent
Glottis
The space between the true folds is the glottis Can be divided into cartilaginous glottis and membranous glottis Membranous forms ant 3/5 Cartilaginous forms post 2/5 (then connects to arytenoids)
Speech Production (Utterances)
Transient Utterances, Extended sustained utterances, running speech activities
Praat
Waveform Spectrogram Spectrum
Muscle activity during phonation
adductors adduct and then stay contracted - no contribution to the actual waves
Increased Medial Compression
increased sub glottal pressure and increased intensity
Mass of Glottal Edges
influenced by degree of abduction or adductions Full mass (full adduction) effect mass (portion adducted)
airflow's relationship to Resistance
inversely proportional
Turbulent Flow
irregular, disorganized, with littler circular whirlpools (eddies) at high velocity and/or through tubes with irregular walls found in largest airways, such as trachea requires greater driving pressure flow is not directly proportional to driving pressure happens when we start bumping into things
Glottal Stiffness
is the result of increased rigidity Accomplished through lengthening (CT) or muscle contraction (TA)
Cricothyroid Joints
it is between each inferior horn of the thyroid and the sides of the cricoid
We natural produce less intensity at lower range
its hard to be super loud at a lower frequency - less resistance because folds are shorter/not stretched
longitudinal phase difference
lag in closure along the anterior and posterior dimensions
Larger tube means _ resistance
less; ie. /a/
Tension in VFs
lots of tension is faster frequency; increased pitch
Viscosity
measure of internal friction of fluid water vs. maple syrup vs. honey (pour vs ooze - more resistant)
Smaller tube means _ resistance
more; ei. /s/
Resistance
opposition to movement airway resistance elastic resistance viscosity
Prephonation Phase
period in which the VF's move from an abducted position to and adducted or partially adducted position (When VF are approximated, sub glottal pressure increases and the velocity of the air throughout the constriction increases) Medial Compression (the degree to which the VF's are approximated) (needs to match speaking intensity means (ie. more medial compression needed for louder)) PTP - tells minimum amount of pressure needed for softer phonation - pipi exercise - wont go below 1cm - ranges between 1 and 3cms - most non pathology are a high 1 LAR - same thing as PTP but at conversational level
Divergent
refer to a closing glottis (upper mass); V shape; - lateral intraglottal pressure
Breathing requires work to over come _
resistance
What creates pressure difference?
shifting of energy from out to in; alternation between divergent and convergent; pressure difference (intraglottal/supraglottal)
Length of VFs
shorter folds have higher frequencies (think of Male, Female, Child)
Spectrum
shows us the frequency components involved in a given moment in time - gives us frequency and amplitude
ABduction
simultaneous movement of both folds away from midline increasing the size of the glottis (lateral movement of the VFs) effected mainly by contraction of PCA muscles pulls muscular processes of arytenoids swinging VFs upward and outward (posterolateral movement)
Adduction
simultaneous movement of both folds toward midline decreasing the size of the glottis close laryngeal airway and there is contact between the free margins of the VFs full (membranous and cartilaginous) or partial (membranous) adduction LCA pulls forward on muscular processes causing arytenoids to rock and swing inward and downward TA also include VF adduction
Arytenoids
sitting on superior posterior portion of cricoid and are posterior to thyroid cartilage Apex (top of triangle) Muscular Process (posterior on cricoid) Vocal Process (anterior on cricoid)
Laminar Airflow
smooth, orderly, uninterrupted, directly proportional to driving pressure
vertical phase difference
some independent motion of the two masses on the vertical dimension
Infrahyoid
sternothyroid, sternohyoid, thyrohyoid**, omohyoid external point of attachment is below the hyoid bone pull larynx down when contracted
We natural produce more intensity in higher range
stretched VF creates more resistance and then we need more pressure to overcome this resistance - breathier because there is a slight space between the folds
Transient Utterances
sudden explosive burst accomplished through full adduction of the VFs - build of pressure in subglottic space - abrupt release (b, p)
fundamental frequency corresponds to
the perceived pitch of the voice
harmonics contribute to
the quality of the voice
Mass in VFs
thicker mass is lower frequency
Extended sustained utterances
turbulent noise of voice production turbulence results from forcing air through a constriction (f, s, z)
2 Mass Model (Description)
upper/lower mass the lower mass leads the upper mass due to asymmetry of the masses different glottal shapes are observed during the different parts of the cycle (convergent/divergent)
Convergent
use to refer to an opening glottis (lower mass); triangular shape; + lateral intraglottal pressure
Lateral VF pressure changes with VF __
velocity (inward/outward)
Airflow
volume of air moving through a given cross section of tubes per unit of time; happens as a result of pressure difference between two points (driving pressure)
Forced Abduction (open to greatest degree possible)
when the glottis is forcefully opened widely to inhale greater amount of air
Cricothyoid
(CT) - pars rectus and pars oblique muscles elongate and lengthen by increasing distance between thyroid and arytenoids.
Interarytenoid
(IA) - transverse and oblique muscles are adductors
Lateral Cricoarytenoid
(LCA) - adducts by rocking arytenoids toward midline
Posterior Cricoarytenoid
(PCA) - abducts by rocking arytenoids away from the midline
Thyroarytenoid
(TA) - Main body of VF External TA (thyromuscularis): near laryngeal wall Internal TA (thyrovocalis): flanks vocal ligament
Larynx (bones and cartilages)
1 Bone (Hyoid) 3 Paired Cartilages (Arytenoids, Corniculate, Cuneiform) 3 Unpaired (Thyroid, Cricoid, Epiglottis)
Step by Step 2 Mass Model
1. adduct - IA and LCA contract 2. Once they're at midline pressure builds up below 3. Pressure starts to push lower border (this energy comes from the airstream) - positive lateral intraglottal pressure (glottal airflow is increasing and accelerates air in supraglottal region) applies to this fold causing outward net velocity (ie. outward movement of VFs) 4. inward net velocity causes the folds to come back together - caused by elastic properties and air pressure difference 5. starts to be overcome by restorative force (shift in the lower border is a force difference/shift as soon as it starts to come back in) this creates less lateral intraglottal pressure because there is less of a margin to push open (and less airflow than convergent) 6. there begins to be an airflow difference between intra and supra glottal regions 7. when they're completely closed you have increased sub glottal pressure and then decreased supra glottal pressure (backflow of air)
Waveform
2d - time and amplitude
Spectrogram
3 axis time on horizontal line vertical is the frequency amplitude is represented in shades of gray in Broad Each one of the vertical striation in the spectrogram shows once cycle ie. glottal pulses In narrow you don't see glottal pulses, but you can see the frequencies
Work of Breathing
Airflow
Attack Phase
Begins with VF's (nearly) adducted and extends through the vibratory cycle
2 Mass Model (Why we use it)
Bernoulli effect NOT account for self-sustained oscillation The two mass Model can be used to explain self-sustained oscillation because it can best explain the wavelike motion
Hyoid Bone
Body Lesser Horn Greater Horn
CA Joint
CA join: up-back-out (abducts and lengthens) OR down-forwad-in (adducts and shortens) PCA contraction lengthens LCA contraction shortens
CT Joint
CT joint: forward pull (from thyroid) or backward pull (from arytenoids) when approximated CT muscles pulls forward by bringing cricoid and thyroid closer together - stretches VFs PCA muscle anchors VFs or pulls them backward and upward shortening results from relaxation of muscles discussed in lengthening or concentric action of TA
Cover-Body Model
Classification of the layers of the VF by differing degrees of stiffness Cover: Epithelium: Thin stiff capsule that determines outer shape of VFs Superficial layer of lamina propria: loose fibrous matrix Transition (vocal ligament) intermediate layer: Elastic Fibers Deep layer: Collagen fibers The body: TA muscle (muscle fibers) Each layer has its own mode of vibration
Two Joints
Cricoarytenoid; Cricothyroid Joints
Frequency
Determined by length, mass, and tension of VF's
Intensity
Determined by regulating sub glottal pressure through increased or decreased medial compression
What accounts for self sustained Oscillation
Glottal asymmetry (convergent and divergent shapes) shifting of energy (shifting of outward and inward net velocity - created by the airflow) pressure difference (airflow is the cause of lateral pressure difference) (pressure differences between supra and intraglottal regions closed vs open)
Extrinsic Muscles of the Larynx
Have one point of attachment to the larynx and the other point of attachment is to a structure outside the larynx Infrahyoid and Suprahyoid
Thyroid Cartilage
Inferior to Hyoid Thyroid Notch Angle Lamina Superior Horn Inferior Horn
Bernoulli Effect
Inverse relationship between pressure and particle velocity specifically, the vocal folds are often described as collapsing together by a negative pressure in the glottis. this DOES NOT describe phonation (anymore) shower; canoes
Full Adduction
LCA and IA
Intrinsic muscles of the Larynx
LCA, IA, PCA, CT, TA
VF Length Changes
Length changes are accomplished through either the cricoarytenoid joint or the cricothyroid joint
Whisper Glottal Shape
Membranous closed and cartilaginous portion open
Partial Adduction
Only LCA
Bernoulli Effect Process
after closure of the vocal folds, subglottal pressure is built up and causes the folds to move outward (laterally), thus opening the glottis VF continues to move laterally until they're overcome by elastic forces. This ceases outward movement. the vocal folds then begin to move medially and are described as collapsing together as a result of the Bernoulli effect. Described as negative pressure causing them to collapse together; inverse relationship between pressure and particle velocity
Cricoarytenoid
articulation between the base of each arytenoid and the superior surface of the cricoid
Valves in the Larynx
aryepiglottic folds (the most superior) false vocal folds (ventricular) (inferior to aryepiglottic folds) (superior and parallel to the true folds) True Vocal Folds (Consists of five layers)
Glottal size and configuration changes
can be attibuted to changes in the physical dimensions of larynx length, diameter, area, and shape largely influenced by abduction and adduction of the VFs
Myoelastic-Aerodynamic Theory
classical description of vocal fold vibration the myoelastic component refers to the muscular and elastic properties of the vocal folds and Bernoulli Effect. The aerodynamic portion of the theory is regard to as the positive subglottic pressure generated by the lung volume
Pharynx
cone shaped musculotendinous tube that forms the posterior portion of vocal tract 3 groups of muscles inferior constrictors middle constructors superior constrictors contraction narrows pharyngeal cavity relaxation widens pharyngeal cavity
Mucosal Wave
continuation of the vertical phase difference it is the rippling of a wave laterally across the superior aspect of the VF
What happens when you increase the length of VF
decrease mass and increased tension when CT stretches the vocal folds the lengthened fold doesn't contribute much to the pitch change - instead it's more the decreased mass and increased tension
Suprahyoid
digastric, stylohyoid, mylohyoid, geniohyoid, hyoglossus, genioglossus external point of attachment is above the hyoid bone pull the larynx upward when contracted
airflow is _ to the driving pressure assuming no change in resistance
directly proportional double pressure = double flow half pressure = half flow
airflow equation
driving pressure/resistance
Friction
force that results in a drag on an object, slowing it down
Outward movement results in __ energy than inward movement
greater
Bernoulli effect can only account for
how the folds suction together
Elastic Resistance
work required to prevent tissue from springing back once deformed