UNIT 2 RESPIRATION & PHONATION

SPPA 4030 Speech Science 1

UNIT 2 RESPIRATION & PHONATION


Structure and Mechanics of Respiratory System

Pulmonary system Lungs and airways

Upper respiratory system Lower respiratory system

Chest wall system Necessary for normal vegetative and speech

breathing


Pulmonary system: lower respiratory tract


Pulmonary system: lower respiratory tract


Chest wall system Rib cage Abdomen Diaphragm


Chest wall-Lung relation Lungs not physically attached to the thoracic walls Lungs: visceral pleura Thoracic wall: parietal pleura Filled with Pleural fluid Ppleural < Patm - “pleural linkage” allows the lungs to move with

the thoracic wall Breaking pleural linkage Ppleural = Patm - pneumothorax


Thorax


Abdomen


Diaphragm


Respiratory muscles Diaphragm External intercostals Internal intercostals (interosseus & intercartilaginous) Costal elevators Serratus posterior superior Serratus posterior inferior Sternocleidomastoid Scalenes Trapezius

• Pectoralis major• Pectoralis minor• Serratus anterior• Transverse throacis• Rectus abdominis• External obliques• Internal obliques• Transversus abdominis• Quadratus lumborum


Moving Air

Vt = Palv

Palv < Patm (- Palv)

P differential = density differential air molecules flowing into lungs = inspiration

Vt = Palv

Palv > Patmos (+ Palv)

P differential = density differential air molecules flow out of lungs = expiration

Patm: atmospheric pressure Palv: alveolar pressureVt: thoracic volume

P = k/V: Boyle’s Law


Changing lung volume ( Vlung)

pleural linkage: Vlung = Vthoracic

Vthoracic is raising/lowering the ribs (circumference)

Raising: Vthoracic = inspiration Lowering: Vthoracic =expiration

Raising/lowering the diaphragm (vertical dimension) Raising: Vthoracic =expiration Lowering: Vthoracic =inspiration


Rest breathing vs. speech breathing

What are the goals?

Rest breathing ventilation

Speech breathing communication ventilation


Quantifying respiratory function What measures would be useful?


Measuring respiratory function

Volume Spirometer

“wet” and “dry” varieties



Pressure Manometer Specialized pressure transducers

measures pressure at specific locations For example,

When swallowed, thoracic and abdominal pressures “inserted” into the trachea for tracheal pressure placed strategically along the vocal tract



Flow Rate Spirometer

nonspeech Pneumotachograph

Airflow during speech and nonspeech Vented mask the covers mouth and nose


SpirometryLu

ng V

olum

e


Lung Volumes

REL


A Review of volumes and capacitiesTidal Volume (TV)

Volume of air inspired/expired during rest breathing.Expiratory Reserve Volume (ERV)

Volume of air that can be forcefully exhaled, “below” tidal volume.Inspiratory Reserve Volume (IRV)

Volume of air that can be inhaled, “above” tidal volume.Residual Volume (RV)

Volume of air left after maximal expiration. Measurable, but not easily so.Total Lung Capacity (TLC)

Volume of air enclosed in the respiratory system (i.e. TLC=RV+ERV+TV+IRV)Functional Residual Capacity (FRC)

Volume of air in the respiratory system at the REL (i.e. FRC=RV+ERV)Inspiratory capacity (IC)

TV + IRVVital Capacity (VC)

Volume of air that can be inhaled/exhaled (i.e. VC=IRV +TV+ERV)


NOTE

Some authors use the term FRC (functional residual capacity) instead of REL (resting end-expiratory level)

Behrman uses resting lung volume (RLV) Refers to equivalent “place” in the lung

volume space


Some typical adult valuesTypical Volumes & Capacities

Vital Capacity (VC) 4-5 liters

Total Lung Capacity (TLC)~ one liter more than VC

Resting Tidal Volume (TV)~ 10 % VC

Resting expiratory end level (REL)~ 35-40% VC when upright

Typical Rest Breathing Values

Respiratory rate12-15 breaths/minute

Alveolar Pressure Palv +/- 2 cm H20

Airflow~ 200 ml/sec


Respitrace



Speech vs. Life BreathingRest Breathing

Volume10 % VC at rest

Alveolar Pressure Palv +/- 2 cm H20

Average Airflow100-200 ml/sec

Ratio of inhalation to exhalation~40/60 to 50/50

Speech Breathing

Volume20-25 % VC @ normal loudness (note Kent reports lower values)40 % loud speechAlveolar Pressure Palv + 8-10 cm H20 on expiration

Average Airflow100-200 ml/sec

Ratio of inhalation to exhalation~ 10/90


Respiratory System Mechanics


Respiratory System Mechanics

It is spring-like (elastic) Elastic systems have an equilibrium point

(rest position) What happens when you displace it from

equilibrium?

SPPA 4030 Speech Science 28equilibrium Longer than

equilibrium

Displacement away from equilibrium

Restoring force back to equilibrium


equilibriumShorter thanequilibrium



SPPA 4030 Speech Science 30equilibriumShorter than

equilibriumLonger thanequilibrium




Equilibrium point ~ REL


RELLung VolumeBelow REL

Lung VolumeAbove REL

Displacement away from REL

Restoring force back to REL


Is the respiratory system heavily or lightly damped?


Respiratory Mechanics: Bellow’s Analogy

Bellows volume = lung volume Handles = respiratory muscles Spring = elasticity of the respiratory system – recoil or

relaxation pressure


No pushing or pulling on the handles ~ no exp. or insp. muscle activity

Volume ~ REL Patmos = Palv, no airflow


muscle force

muscle force

elastic force

pull handles outward from rest V increases ~ Palv decreases Inward air flow INSPIRATION

At REL


muscle force

muscle force

elastic force

push handles inward from rest V decreases ~ Palv increases outward air flow EXPIRATION

At REL


Respiratory Mechanics: Bellow’s Analogy

Forces acting on the bellows/lungs are due to Elastic properties of the system

Passive Always present

Muscle activity Active Under nervous system control (automatic or voluntary)


Forces due to elasticity of system(no active muscle activity)

Recoil forces are proportionate to the amount of displacement from rest

Recoil forces ~ Palv

Relaxation pressure curve Plots Palv due to recoil force against lung volume


Relaxation Pressure Curve (as in Behrman)


Relaxation Pressure Curve(Our version)

42

% Vital Capacity40 0100

0

Alv

eola

r Pre

ssur

e (c

m H

20)

20

40

60

-20

-40-60

80 60 20

relaxation pressure REL


Breathing for Life: Inspiration

pulling handles outward with net inspiratory muscle activity


Breathing for Life: Expiration

No muscle activity Recoil forces alone returns

volume to REL

45% Vital Capacity

40 0100

0

Alv

eola

r Pre

ssur

e (c

m H

20)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

10 %

~ 2 cm

Breathing for Life


Respiratory demands of speech Conversational speech requires

“constant” tracheal pressure for driving vocal fold oscillation

brief, “pulsatile” changes in pressure to meet particular linguistic demands emphatic and syllabic stress phonetic requirements


Respiratory demands of speech Conversational speech

Volume solution Constant tracheal

pressure 8-10 cm H20 Pulsatile solution

Brief increases above/below constant tracheal pressure

Driving analogy Volume solution

Maintain a relatively constant speed

Pulsatile solution Brief

increases/decreases in speed due to moment to moment traffic conditions


Example

Time

Pres

sure

wrt

atm

osph

ere

0

-5

5

10

49

Breathing for Speech: Inspiration

pulling handles outward with net inspiratory muscle activity

Rate of volume change is greater than rest breathing

50% Vital Capacity

40 0100

0

Alv

eola

r Pre

ssur

e (c

m H

20)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

20 %

~ 8-10 cm

Breathing for Speech

51% Vital Capacity

40 0100

0

Alv

eola

r Pre

ssur

e (c

m H

20)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

20 %

~ 8-10 cm


52

Breathing for Speech: Expiration

Expiratory muscle activity & recoil forces returns volume to REL Pressure is net effect of expiratory

muscles (assisting) and recoil forces (assisting)

53% Vital Capacity

40 0100

0

Alv

eola

r Pre

ssur

e (c

m H

20)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

20 %

~ 8-10 cm



Summary to this pointMuscle activity for Inhalation Life

Active inspiration to overcome elastic recoil Speech

Active inspiration to overcome elastic recoil Greater lung volume excursion

Longer and greater amount of muscle activity Rate of lung volume change greater

Greater amount of muscle activity


Summary to this pointMuscle activity for exhalation Life

No active expiration (i.e. no muscle activity) Elastic recoil force only

Speech Active use of expiratory muscles to maintain airway

pressures necessary for speech (8-10 cm water) Degree of muscle activity must increase to offset

reductions in relaxation pressure


This meets our needs to provide ‘constant’ pressure of 8-10 cm H20

What about meeting our ‘pulsatile’ pressure demands?


What is required to provide these pressure ‘pulses’? Brief, robust expiratory muscle activity We need a ‘well-tuned’ system

Chest wall must be ‘optimized’ so that rapid changes can be made

Optimal environment created by active muscle activity

A ‘modern’ view of speech breathing


What we know now vs. then “Classic” studies of speech breathing

University of Edinburgh Draper, Ladefoged & Witteridge (1959, 1960)

“Contemporary” studies of speech breathing Harvard University Hixon, Goldman and Mead (1973) Hixon, Mead and Goldman (1976)


What we know then and now

Then Inspiratory muscles

only

Now Coactivation of Rib cage (insp) Abdomen (exp) ‘net’ inspiration

Net Inspiratory Muscle Pressure



Then All muscles are silent

Now Coactivation of

Rib cage (insp) Abdomen (exp) System ‘balanced’

Net Zero Muscle Pressure



Then RC muscles

Now Rib cage (exp) Abdomen (exp)

Net Expiratory Muscle Pressure


Interpretation of information Constant muscle activity may serve to “optimize”

the system in various ways

For example, Abdominal activity during inspiration pushes on, and stretches the diaphragm Optimal length-tension region of diaphragm Increase ability for rapid contraction which is needed

for speech breathing


Interpretation of information Constant muscle activity may serve to “optimize”

the system in various ways

For example, Abdominal activity during expiration Provides a platform for rapid changes in ribcage

volume (pulsatile) Without constant activity, abdomen would ‘absorb’

the forces produced by the ribcage


So what? Suggests speech breathing is more ‘active’

than originally thought Passive pressures (recoil forces) of the system

is heavily exploited in life breathing speech breathing requires an efficient pressure

regulator and therefore relies less on passive pressures


Summary: Muscle activityInspirationLife Active inspiratory musclesSpeech COACTIVATION OF

inspiratory muscles expiratory muscles

(specifically abdominal) INS > EXP = net inspiration System ‘tuned’ for quick

inhalation

Expiration

Life No active expiration (i.e. no

muscle activity)Speech Active use of rib cage expiratory

muscles Active use of abdominal

expiratory muscles System “Tuned” for quick brief

changes in pressure to meet linguistic demands of speech


Summary: Muscle activityNo AirflowLife Minimal muscle activitySpeech Coactivation of

Rib cage (inspiratory) Abdomen (expiratory) System ‘balanced’


Lifespan considerations (Kent, 1997)

Respiratory volumes and capacities until young adulthood young adulthood to middle age during old age

stature elastic properties muscle mass



Maximum Phonation Time (MPT) Longest time you can sustain a vowel Function of

Air volume Efficiency of laryngeal valving

Follows a similar pattern to respiratory volume and capacities



Birth Respiration rate 30-80 breaths/minute Evidence of ‘paradoxing’ Limited number of alveoli for oxygen exchange



3 years Respiration rate 20-30 breaths/minute Speech breathing characteristics developing


Lifespan considerations (Kent, 1997) 7 years

Adult-like patterns > subglottal pressure than adults Number of alveoli reaching adult value of 300,000

10 years Functional maturation achieved

12-18 years Increases in lung capacities and volume


Clinical considerations Parkinson’s Disease Cerebellar Disease Spinal cord Injury Mechanical Ventilation


Parkinson’s Disease (PD) Rigidity, hypo (small) & brady (slow) kinesiaSpeech breathing features muscular rigidity stiffness of rib cage abdominal involvement relative to rib cage ability to generate Ptrach modulation Ptrach Speech is soft and monotonous


Cerebellar Disease dyscoordination, inappropriate scaling and

timing of movementsSpeech breathing features Chest wall movements w/o changes in LV

(paradoxical movements) fine control of Ptrach Abnormal start and end LV (below REL) speech has a robotic quality


Spinal cord injury Remember those spinal nerves… Paralysis of many muscles of respirationSpeech breathing features variable depending on specific damage abdominal size during speech control during expiration resulting in difficulty

generating consistent Ptrach and modulating Ptrach Treatment: Support the abdomen (truss)


Mechanical Ventilation Breaths are provided by a machineSpeech breathing features control over all aspects of breath support Length of inspiratory/expiratory phase Large, but inconsistent Ptrach Inspiration at linguistically inappropriate places Speech breathing often occurs on inspiration Treatment: “speaking valves”, ventilator adjustment,

behavioral training


Other disorders that may affect speech breathing

Voice disorders Hearing impairment Fluency disorders Motoneuron disease (ALS)

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UNIT 2 RESPIRATION & PHONATION