Breathing and Speech Production SPPA 4030 Speech Science

SPPA 4030 Speech Science

Breathing and Speech Production


Learning Objectives

• Possess a basic knowledge of respiratory anatomy sufficient to understand basic respiratory physiology and its relation to speech sound generation.


Respiratory System Components


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


Chest wall system

• Rib cage wall• Abdominal wall• Diaphragm• Abdominal contents


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


Learning Objectives

• Describe how physical laws help explain how air is moved in and out of the body.


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 thoracic volume (Vt)

Strategies• ∆ Length• ∆ Circumference


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


Biomechanics of the chest wall


Learning Objectives

• Contrast the goals of non-speech breathing and speech breathing.


“Goals” of Breathing

• Non-speech (e.g. rest) Breathing– Ventilation

• Requires exchanging volumes of air

• Speech Breathing– Ventilation

• Requires exchanging volumes of air

– Communication• Requires regulating alveolar pressure on expiration


Learning Objectives

• Outline the output variables associated with breathing.

• Briefly describe the methods used to measure lung volume change.

• Describe the functional subdivisions of the lung volume space.

• Be aware of the lungs volumes required for various respiratory activities.

• Differentiate speech and rest breathing in terms of volume measures.


Output Variables: Volume

• “Wet” Spirometer– Volume measured

directly



• Pneumotachograph– Sometimes called “dry”

spirometry– Vented mask the covers

mouth and nose– Airflow signal is then

integrated to determine volume



(REL)


Lung Volume Terminology• Tidal 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)• Inspiratory capacity (IC)

– TV + IRV• Vital Capacity (VC)

– Volume of air that can be inhaled/exhaled (i.e. VC=IRV +TV+ERV)• Functional Residual Capacity (FRC)

– Volume of air in the respiratory system at the REL (i.e. FRC=RV+ERV)• Resting Expiratory End Level/Resting Lung Volume (REL or RLV)

– Place in lung volume space where resting tidal volume typically ends



Output Variables: VolumeTypical Volume Values• Vital Capacity: 4-5 liters• Total Lung Capacity: 5-6 liters• REL: 40 % VC (upright)Rest Breathing• Tidal Volume: ~ 10 % VC• Insp/Exp Timing: ~50:50• Respiratory Rate: 12-15

breaths/minuteSpeech Breathing• Tidal Volume: 20-25 % VC• Insp/Exp Timing: ~10:90• Respiratory Rate: variable

Rest Breathing vs. Speech Breathing


Learning Objectives

• Briefly describe the methods used to measure/infer alveolar pressure.

• Contrast speech and rest breathing in terms of alveolar pressure.

• Be aware of the alveolar pressure required for various respiratory activities.


Output Variables: Pressure

• Termed Manometry• pressure transducers

may be placed at various locations in the body– Mouth– Trachea– Thoracic esophagus– Abdominal esophagus


Quantifying aerodynamic Pressure


Output Variables: Pressure

Typical Values

Resting Tidal BreathingPalv: +/- 1-2 cm H20

Speech BreathingPalv: +8-10 cm H20 during expiration


Learning Objectives

• Briefly describe methods used to measure changes in chest wall shape.

• Be aware of the factors that influence changes in chest wall shape.


Output Variables: Shape

• Rib cage wall and abdominal walls are free to move

• Changing either can influence lung volume• A wide variety of chest wall configurations are

possible.• Configurations appear to be a function of

biomechanical and task-based factors.







Volume, pressure and Shape Changed during speech breathing


Learning Objectives

• Describe the elasticity of the respiratory system and its relation to REL.

• Apply the bellows analogy to the respiratory system.


Respiratory System Mechanics

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

position)• What happens when you displace it from

equilibrium?

equilibrium Longer thanequilibrium

Displacement away from equilibrium

Restoring force back to equilibrium



equilibriumShorter thanequilibrium




equilibriumShorter thanequilibrium

Longer 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


At REL

muscle force

muscle force

elastic force

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


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)


Learning Objectives

• Use the modified pressure-relaxation curve to explain the active and passive forces involved in controlling the respiratory system.

• Provide muscular solutions for producing target alveolar pressures at various regions of the lung volume space.

• Differentiate between volume and pulsatile demands during speech breathing.

• Outline the differences in the muscular strategies used for rest and speech breathing.


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


Traditional Relaxation Pressure Curve

Hixon, Weismer & Hoit


Relaxation Pressure Curve(Our modified version)


% Vital Capacity

40 0100

0

Alv

eola

r P

ress

ure

(cm

H20

)

20

40

60

-20

-40

-6080 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


% Vital Capacity

40 0100

0

Alv

eola

r P

ress

ure

(cm

H20

)

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


Breathing for Speech: Inspiration

pulling handles outward with net inspiratory muscle activity

Rate of volume change is greater than rest breathing


% Vital Capacity

40 0100

0

Alv

eola

r P

ress

ure

(cm

H20

)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

20 %

~ 8-10 cm

Breathing for Speech


% Vital Capacity

40 0100

0

Alv

eola

r P

ress

ure

(cm

H20

)

20

40

60

-20

-40

-6080 60 20

relaxation pressure

20 %

~ 8-10 cm

Breathing for Speech


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)

% Vital Capacity

40 0100

0

Alv

eola

r P

ress

ure

(cm

H20

)

20

40

60

-20

-40

-6080 60 20

20 % VCchange

Target Palv ~ 8-10 cm

Optimal regionPrelax > 0assists Palv

Add Pexp to Meet Psg

Prelax: relaxation pressurePalv: target alveolar pressurePexp: net expiratory muscle pressurePinsp: net inspiratory muscle pressure

Below RELPrelax < 0opposes Palv

Add Pexp to meet Palv

& overcome

Prelax

Prelax > Palv

Requires “braking”Add Pinsp to Meet Palv


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

– Minimal 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


Learning Objectives

• Explain how the respiratory system is “tuned” for speech breathing.


Speech breathing demands a ‘well-tuned’ respiratory system

• Brief, robust expiratory muscle activity• Chest wall must be ‘optimized’ so that rapid

changes can be made• Optimal environment created by active muscle

activity• This is our ‘modern’ view of speech breathing


History of Speech Breathing Studies

• “Classic” studies of speech breathing– University of Edinburgh– Draper, Ladefoged & Witteridge (1959, 1960)

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


How do we tune our system?

• Abdominal wall is active throughout the speech breath cycle –even during inspiration!

• Why??• Speculations include

– Stretches diaphragm and rib cage muscle to a more optimal length-tension region, which increases ability for rapid contraction to meet pulsatile demands.

– During expiration, a strong abdominal platform prevents energy being ‘absorbed’ by the abdominal contents.


Optimizing the chest wall


Muscle ActivityRib Cage Wall (inspiratory)

Rib Cage Wall (expiratory)

Abdominal Wall


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


Learning Objectives

• Describe how body position can affect speech breathing patterns.


Role of Position on Breathing




Sustained VowelUpright Position

Sustained VowelSupine Position


Learning Objectives

• Describe how various respiratory impairments can lead to diminished speech production abilities.


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 movements

Speech 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)

Documents

Breathing and Speech Production SPPA 4030 Speech Science