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