Speech Science Midterm

Speech Breathing

Regulation of breathing for voice and speech production; SLPs work w/ clients to work with clients with speech and voice problems

Breathing

Inhalation (inspiration) and Exhalation (expiration)

Respiration

Gas exchange on the cellular level; bringing O2 in and CO2 out via simple diffusion

Ventilation

Moving air in and out of the lowering airway

Boyle’s Law

as volume of a space increases, the pressure decreases (and vice versa)

Lung Expansion

Pressure drop within the lungs (negative pressure) - air flows in

Lung Contraction

Pressure increase within the lungs (positive pressure) - air flows out

Pulmonary System

Lungs and airways (URS and LRS)

Chest Wall System

Ribs, abdomen, and diaphragm

LRS

Larynx, alveoli, bronchial tree; begins with trachea, 10-16 cm long w/ 20 rings to provide flexibility and support

Anatomy of lower airway

rib cage - 12 sets of ribs

trachea - lined with cilia to filter pollutants

bronchial tree

lings - 5 lobes (90% air)

Lungs

Bronchial Tree: each subdivision yields smaller bronchioles

• level of gas exchange = alveoli

• diffusion must occur quickly

• large surface area with permeable membrane for diffusion w/ the concentration gradient

Alveolar Sacs

Respiratory bronchioles open into alveolar ducts leading into alveolar sacs

• kept inflated by surfactant

Muscles for breathing

Neck, thorax, back, abdomen (function - inhalation and exhalation)

• inhalation: diaphragm and external intercostals

• exhalation: internal intercostals

** Rib cage expands in 3 directions (F-B, S-S, T-B)

Major muscle of inhalation

Diaphragm (regulates volume of thoracic cavity)

External intercostals

Pull the rib cage up and out during inspiration; increasing volume of thoracic cavity

Internal intercostals

Pull rib cage down; decreasing volume of thoracic cavity

Three functions of all muscles of breathing

1) Breathing (changing volume of lungs)

2) Posture (core stabilization); may increase efficiency

3) Movement (bending, turning, etc)

Breathing at rest

Quiet tidal breathing

Two forces enable lungs to change volume

1) Restorative forces of tissues

2) Plural linkage

Pleural linkage

• Parietal and visceral pleura

• Negative intrapleural space (w/ fluid)

Maintains the expansion of the lungs and the compression of ribcage

Transpulmonary pressure

Difference between pressure in lungs (alveoloar) and intrapleural pressure

Breath cycle

1) Diaphragm contacts (flattens downward)

2) PM stretched causing drop in pressure

3) Abdominal structures are compressed and abdomen protrudes outward

4) External intercostals contract a bit to stiffen walls of thorax which increases efficiency of diaphragm. (Large movement of external intercostals not necessary in tidal
breathing.)

5) Air rushes inward to equalize pressure

6) The expansion of the lungs and the lowered intrapleural pressure increase elastic recoil force

7) Diaphragm & external intercostals relax and together with recoil forces, lungs & thoracic cavity decrease in volume and air rushes out

EXHALATION IS PASSIVE IN TIDAL BREATHING

Average number of breaths per minute in tidal breathing

12-15 breaths

When air pressure (𝑃𝑎𝑙𝑣) inside the lungs is negative

air is forced to enter the respiratory system (because air moves from areas of high pressure to areas of low pressure)

When air pressure (𝑃𝑎𝑙𝑣) inside the lungs is positive

air is forced out of the respiratory system into the atmosphere

To decrease (Palv)

Must increase the volume of the thoracic cavity and lungs; contract the diaphragm, which flattens out and increases the vertical dimension of the thorax
▪ External intercostals pull the ribcage up and out
▪ The lungs, attached by pleural linkage, are pulled in the same direction as the
thoracic cavity and therefore increase in volume

To increase (Palv)

Must decrease the volume of the thoracic cavity and lungs; relax the diaphragm back to its dome-shaped position
▪ We relax the external intercostals, allowing the rib cage to return to its original
position

At the end of each inhalation and exhalation cycle

There is a brief moment in which air does not move into or out of the
respiratory system
- 𝑃𝑎𝑙𝑣 equals 𝑃𝑎𝑡𝑚𝑜𝑠 - (REL)

Lung volume

Single, non overlapping value

Lung capacity

2+ volumes

Tidal volume (TV)

the volume of air that we breathe in and out during a cycle of respiration

Inspiratory reserve volume (IRV)

The amount of air that can be inhaled above TV

Expiratory reserve volume (ERV)

The amount of air that can be exhaled below the TV

Residual volume

the amount of air always in the lungs that cannot be exhaled voluntarily
-lung tissue is always slightly stretched due to pleural linkage; therefore, there must be
some air pressure in the lungs

Vital capacity

The maximum amount of air a person can exhale after a maximum inhalation (the total amt.of air available for ALL purposes)
VC = IRV + TV + ERV

Functional residual capacity

The amount of air remaining at the resting expiratory level or end expiratory level
FRC = ERV + RV

Inspiratory capacity

The amount of air that can be inhaled from the end-expiratory level
IC=TV+IRV

Total lung capacity

The total amount of air the lungs can hold
TLC = TV + IRV + ERV + RV

Relaxation Pressure

Act to return the breathing system to REL

• positive when it acts to decrease lung pressure

• negative when it acts to expand lung volume

Active forces

Muscle contraction

Passive forces

Gravity, elastic recoil, surface tension of alveoli

Relaxation curve

Relaxation pressure as a function of lung volume displayed graphically

Thorax

Compressed spring & its elastic recoil exerts an expansion force

Lungs

Stretched spring with elastic recoil exerting a compression force

Relaxation Curve

Pressures generated by the elastic recoil forces at different
percentages of vital capacity

A on the RC

At the bottom of vital capacity, the elastic recoil forces acting on the lungs to decrease their overall volume are minimal

B on RC

At resting lung volume, the relaxation pressure is balanced such that the elastic recoil forces acting to expand the chest wall are equal to the forces acting to decrease lung volume.

C on RC

As vital capacity increases, a point is reached in which the chest wall is at its resting size.

D on RC

At max vital capacity, elastic recoil forces of the chest wall and lungs are acting to decrease overall lung volume

Resting expiratory level (38% vital capacity)

Forces are balanced

Curve below RLV

Relaxation pressures working to increase lung volume (negative)

Curve above RLV

Relaxation pressures working to decrease lung volume (positive)

Average rate of breathing for speech breathing

12 to 20 breaths/minutes, but the balance of inspiration to expiration differs

Tidal breathing I/E phases

40% (Inspiration) 60% (Expiration)

Speech breathing I/E phases

10% (Inspiration) 90% (Expiration with speech)

Hixon, Mead, & Goldman (1976)

Passive relaxation pressure alone is never the solitary force managing speech breathing. Active muscle force always contributes.
▪ Diaphragm, rib cage inspiratory muscles and abdominals
are all active to varying degrees at the beginning of an
utterance. Abdominals are more continuously active in
speech breathing than in tidal breathing.

• direct relationship between lung volume and and inspiratory muscle force

• indirect relationship between lung volume and expiratory muscle force

Adaptive Control

Changeable internal & external demands require speech breathing system to be highly
adaptable

Body Type

Endomorphs use greater abdominal wall activity over that of the rib cage compared to ectomorphs

• Additional mass on abdomen exerts a pulling force that tugs on diaphragm (flattening effect), inhibiting rapid contraction of diaphragm needed for speech
  

Cognitive-Linguistic Variables

Basic mechanisms of speech breathing are preserved, but timing of inspiratory & expiratory events are altered.
▪ Inspiration occurs mainly at grammatical and semantic boundaries.
▪ Length of phrase & depth of inspiration are directly related.
▪ Cognitive load influences timing

Speech breathing personality

Different styles of breathing relative to activity of the thorax and abdomen

Clavicular breathing

Over-activation of sternocleidomastoid and other shoulder muscles with lesser activation of diaphragm. Lateral expansion of thorax is limited, with emphasis on vertical expansion.
▪ Marked by distinct upward movement of the shoulders or clavicle.
Individuals with neurologic or lung disease may use to compensate for
impaired function (highly inefficient for lung expansion in health
individuals)

Chest (pear shape up, up & in, high breathing)

Activation of abdominal muscles limits downward excursion of diaphragm, but
▪ Antero-posterior expansion of chest wall exerts lateral pull on
diaphragm, allowing vertical expansion of lungs.
▪ May be advantageous in vocal tasks demanding increased breath support, such as singing

Diaphragmatic (pear shape down, down & out, low breathing)

Antagonist muscle contraction of abdomen and thorax are minimized (except for postural stabilization)
▪ As a result the abdominal contents are distended outward, offering less resistance to the diaphragm, which is allowed to contract and flatten.
▪ Optimal style, the target pattern in speech and voice therapy

Respiratory Demands

Our bodies must integrate the demands of speech production with the metabolic demands of gas exchange, of getting oxygen into our blood so that we stay alive

Hyperventilation

over-breathing; excess of CO2 (dizziness, blurred vision, numbness & tingling)

Hypoventilation

(under breathing; too little O2 (impaired cellular respiration, tissue damage, death)

In speech breathing (compared to tidal)

• Ventilation rates higher
  ▪ Slight hypoventilation
  ▪ Irregular breathing, including breath-holding after speaking for short periods to normalize blood gas

During exercise

Larger amounts of air must be moved faster

• Length of phrase breath group decreases.
  ▪ Expiratory time decreases.
  ▪ Larger lung volumes used.
  ▪ Rate of speech unaltered

Neural Control of Breathing

Sensorimotor pathways that mediate respiration for metabolic demands are modulated during speech production

• Breathing is a reflex arising from the respiratory center in the medulla oblongata.
  ▪ Motor control: Phrenic and intercostal nerves and other spinal nerves

Sensory receptors

▪ Chemoreceptors (sensitive to CO2, pH, O2)
▪ Mechanoreceptors (tissue distortion)
▪ Muscle spindles (in muscles: respond to stretch)
▪ Stretch receptors in bronchioles & alveoli

Airflow

volume of air moving through a given cross section of tube per unit of time; driving pressure/resistance

Relationship between airflow and driving pressure

Airflow directly proportional driving pressure
▪ double pressure, double flow
▪ halve pressure, halve flow

Resistance

Opposition to movement (airway, elastic, viscosity)

• airflow is inversely proportional to resistance

Airway resistance

Narrowness of tubes that make up the airway;

• Doubling the airway diameter decreases resistance by a factor of 16 (and vice versa)

• Larger lung volume (inhalation) distends airway, lowering resistance

Turbulent flow is most commonly found in

At high velocity and/or through tubes with irregular walls
▪ Found in the largest airways, such as the trachea
▪ Requires greater driving pressure
▪ Flow is not directly proportional to driving pressure

Elastic Resistance

Work required to prevent tissue from springing back once deformed (in order to change
the volume of the thoracic cavity and lungs)

• Quiet breathing: work of breathing is ~5% of our total metabolic rate

Viscosity

Measure of internal friction of fluid
▪ In a sauna, you may have noticed more difficult to breathe. That is because the extra moisture adds to the overall viscosity of the air.

Phonation

Process of sound generation by vocal fold vibration

• Vocal folds vibrate rapidly open and closed to produce puffs of air consisting of a oscillating air molecules that together produce a sound pressure wave that travels up the vocal tract

Larynx

From the root of the tongue to the trachea in the anterior neck or throat
▪ Level of C4–C6

• Airway protection
  ▪ Throat-clearing, coughing, Valsalva maneuver
  ▪ Participate in regulation of airflow during breathing
  ▪ Stabilize upper body during movement (such as lifting a
  heavy object, running upstairs)

• Phonation!

3 unpaired cartilages

Cricoid, thyroid & epiglottis

Extrinsic

have at least one attachment point outside of the larynx (e.g., hyoid) and anchor the larynx

Intrinsic

confined entirely within the larynx

Conus elasticus

▪ Medial cricothyroid ligament
▪ Lateral cricothyroid membrane (free border superiorly = vocal ligament)

Quadrangular Membrane

Superior Free margins = aryepiglottic folds
▪ Inferior free margins = ventricular ligaments (false vocal folds)

The larynx contains 3 sets of valves or folds

The aryepiglottic, the false (ventricular), and the true vocal folds

Aryepiglottic folds

Run from the sides of the epiglottis to the apex of each arytenoid cartilage.

• They contract to pull the epiglottis backward and to close the entrance of the larynx during swallowing

False vocal folds

Capable of limited movement-they close during swallowing and effortful activity

True vocal folds

most complex valves and are the vibrating element of the larynx

Vestibule

Supraglottic space

Ventricles

Contain mucous glands to lubricate vocal folds

Glottis

Space between the true vocal folds

lateral cricoarytenoid muscle (LCA)

One of the two vocal fold adductors; It closes the glottis

Interarytenoid muscle (IA) (transverse and oblique)

vocal fold adductor/closes the glottis

Posterior cricoarytenoid muscle (PCA)

Only muscle that abducts (opens) the vocal folds

Cricothyroid muscle (CT)

Consists of pars recta & pars oblique; regulates vocal pitch by elongating and tensing the vocal cords

Extrinsic Muscles

Connect cartilages to external point of attachment
▪ Include many infrahyoids; muscles of jaw & strap (large shoulder & neck)
▪ Larynx is suspended from above by extrinsic muscles (as well as attached inferiorly
by ligaments)

Subglottal space

Space under the vocal folds

Supraglottal space

Space above vocal folds

Vocal fold histology (superficial to deep)

Epithelium: stratified squamous cell; plicae
▪ Lamina Propria - 3 layers critical to vocal fold vibration
▪ Superficial (Reinke’s space): consistency like gelatin
▪ Intermediate: composed of elastin
▪ Deep: composed of collagen
▪ Muscle (TA)