Respiration: from Physiology to Phonetics

1. Respiration: fromPhysiology to Phonetics Alain Marchal Laboratoire Parole et Langage CNRS – Aix-en-Provence

2. F. Rohrer (1925): Treatise on respiratory movements: the basis of Respiratory Physiology. • W. Fenn: Extension of this work in the 1940s. • Ladefoged et al. (1957): First phonetic studies examining the relationship between respiration and phonation. • The way in which respiration is modified to accommodate speech production.

3. Vital Function of Respiration • To ensure the exchange of gases between air and blood. • The respiratory cycle comprises two phases: inhalation and exhalation. • Inhalation: Intake of air into the lungs, bringing oxygen to the organism. • Exhalation: Emptying the lungs and expelling the carbon dioxide accumulated by the blood.

4. The Lungs • Situated in the rib cage, • 2 lungs: - shape of air-filled pyramids, - separated by the mediastinum • Divided into two bronchial tubes, subdividing into bronchioles and alveoli.

5. The twolungs are envelopped in a serous membrane: the pleura. 2 layers: visceral and parietal. The pleural fluidallows the layers to slide over one another; The pleura ensures the functionalcouplingbetween the chestwall and the lungs.

6. Mechanics of breathing The lungs and thorax have elastic properties: The property of elasticity plays a great role in normal respiration: - elongation during inhalation - return to rest position during exhalation due to the relaxation forces. Elasticity can be estimated using the pleural pressure

7. The Respiratory System - The Structural Supports • 1– The rib cage • 2– The visceral thorax • 3- The respiration muscles • The rib cage : 12 spinal vertebrae, 12 pairs of ribs, : The sternum. Bounded at the top by the neck and at the bottom by the diaphragm.

8. Rib Cage = Protective shield From Marchal (2007)

9. Head of each rib joined to the spinal column by sliding joints. Displacement of the ribs = enlargement of the cage - Raising of the ribs: transverse and lateral increase - Forward and upward movement of the sternum: increase of the antero-posterior diameter. Movements of the diaphragm: vertical dimension.

10. Some Principles of Aerodynamics • Boyle’s law: When the dimensions of a container are enlarged, its volume increases; the molecules of air become more spaced out, and air pressure falls. • Conversely, when the dimensions are reduced, the volume decreases, the air molecules become compressed, and the pressure increases • The pressure of air in the lungs depends on the force exerted on the thoracic walls by the molecules of air inside them.

11. Some Principles of Aerodynamics • An increase in pulmonary volume > lowering of pressure which results in the drawing in of air from outside. • A decrease in pulmonary volume > increase in pressure which pushes the air out.

12. How to Measure Air Pressure ? • The U tube manometermeasures the height of a column of water when a given pressure isapplied to one arm of the tube • Electronictransducers for dynamic speech pressure measurements are nowused

13. Air Pressures in the Vocal Tract • Pressure isdefined as the force per unit area acting perpendicular to a surface • Absolute pressure is of little value to the speech scientist or speech therapist • Pressures in the respiratory tract (vocal tract) are expressed relative to the atmospheric pressure = gauge or gage pressure • Speech pressures are commonlyexpressed in CmH2o

14. Airflow • Airflowoccurswhenthereis a differencebetween pressures; Air flowsfrom a region of high pressure to one of low pressure. The bigger the difference, the faster the flow • When flow islow and throughnarrow tubes, it tends to flow in a straight line: Laminarairflow • When air flowsathighervelocities, flow isdisorganized, chaotic and formseddies: Turbulent airflow

15. How to Measure Flow ? • Spirometer: • Basic equipment for pulmonaryfunction tests • Differential pressure transducers for the measurement of flow rates • Unsuited for speech

16. How to Measure Flow during a Speech Task ? • Pneumotachograph • Measurement of pressure differencesacross a fine mesh • Electronictransducers of various types • For speech • Airtightmaskwhichfits over the mouth and nose • Mouthmask and catheter in nostrils • Microphone • Body plethysmograph

20. Recording Session with EVA2 in Aix

21. Normal Respiration Inhalation: • Contraction of the external intercostal muscles and of the diaphragm > raising and widening the rib cage > Increase of the pulmonary volume. • The intrapulmonary pressure > negative relative to the atmospheric pressure > the lungs fill by aspiration. • Air intake: about 1/2 liter

22. Normal Respiration Exhalation: • Normal exhalation is an entirely passive, involuntary process caused by the elastic recoil of the pulmonary tissue and the ribs. • Return to equilibrium. • Air out: same volume as intake

23. Aerodynamic Data for Normal Respiration • Ratio between inhalation and exhalation is 1:1. • Rate is 12 to 18 cycles per minute. • Flow: 0,3 -0,5 L/s • Volume: 500 cm3 • Pulmonary Pressure: 1-3 cm H2O • (With forced inhalation and severe muscular effort during exhalation, the rate of flow can increase to more than 50 l/s and intra-pulmonary pressure can go up to 100 cm H2O).

24. Respiration Muscles • The 3 dimensions of the rib cage (vertical, transversal and antero-posterior increase during inhalation and decrease during exhalation. • muscles of inhalation

26. Respiratory Muscles for Inhalation

27. Inhalation Muscle: action of the diaphragm • The diaphragm: • Flattens the dome • Pushes the abdominal organs down • Enlarges the thoracic cavity in the vertical dimension.

28. Action of the Thoracic Muscles in the Inhalation Phase AfterHardcastle, 1976 The external intercostals: Rotation outwards and upwards: Antero-posterior dimension increase. Supplementary muscles: Major and minor pectoral muscles , Scalene muscles.

29. Exhalation Muscles • In normal respiration, exhalation is an entirely passive phenomenon due the combination of the forces of relaxation: the lungs deflate and return to their rest position. • Inforcedrespiration, supplementary pressure must be exerted on the rib cage to prolong the exhalation phase. • This action results from the working of three groups of muscles: the thoracic, the abdominal and the dorsal muscles

30. Exhalation Muscles • The thoracic muscles: • the internal intercostals and the transverse thoracic • The abdominal muscles: • the transverse abdominal, the internal and external oblique and the rectus abdominis • - The dorsal muscles: • the great dorsal and the iliocostal. • The internal intercostals are the most important of the exhalation muscles. 

33. Action of someThoracic Muscles in the Exhalation Phase After Hardcastle, 1976

34. Pulmonary Capacity and Pulmonary Volume

35. Pulmonary Capacity and Pulmonary Volume • Pulmonary volume = quantity of air that the lungs contain • Ventilation amplitude = fn ofoxygen need • Total pulmonary volume = total lung capacity • Residual volume = Air in the lungs after forced exhalation • Vital capacity. Quantity of air that can be expired down to the residual volume. The vital capacity is important for determining how long phonation can be maintained whether for singing or speaking • Tidal volume. The difference between the inhaled and exhaled volumes in normal respiration • Expiratory reserve = difference between the residual volume and the tidal volume.

36. Respiration in Phonation • Normal respiration is automatic • Respiration in speech is very finely controlled: • to allow for breathing and simultaneously producing a complete utterance • without a need for taking a breath at an inappropriate moment.

37. Control of Respiration during Speech • Respiration must thus be modified to increase the volume of available air: - increase of inhalation, - control of exhalation to prolong and regulate the output of air. • Exhalation must provide an output of air sufficient • to maintain stable subglottal pressure for the whole duration of the utterance.

38. The respiratory cycle during Speech • The respiratory cycle is profoundly altered by speech production The ratio between inhalation and exhalation > 1:4 and up to > 1:10 • Inhalation is much faster (via the mouth rather than the nose), to avoid lengthy interruptions. • Exhalation > Longer: from 2-3 seconds in resting respiration to 15-20 seconds, varying according to the length of the utterance. • Pulmonary volume: About 1 l.; double that of resting respiration. Half that of vital capacity.

39. Exhalation isorganized in Breath Groups (after Lieberman, 1965)

40. Declination line of Fo fromstart to end of a breath group The pitch span as the range of Fo values : baseline and plateau (afterVaissière, 1983)

41. Muscular Control during Exhalation for Speech after Ladefoged (1967) At the start of exhalation, the inhalation muscles: external intercostals • Then : the exhalation muscles • Increasingly strong contractions of the internal intercostals compress the rib cage and force out the air remaining in the lungs. • Towards the end of exhalation, their action is reinforced by the exhalation accessory muscles

42. SomeNeglectedAerodynamic Issues • Transglottal pressure = Subglottal pressure - intraoral pressure • Subglottal pressure Level of intensity • Subglottal pressure and laryngeal tension Fo • Consonantal constrictions and closures modify the impedance of the buccal cavity • Consonantal closures change intraoral pressure. • For a given laryngeal state, why changes of intraoral pressure do not necessarily result in Fo variations ? • How can the absence of continuous variations of intensity be explained ?

43. Recording of some of the Respiratory Muscles Simultaneousrecording of the pulmonary volume, the acoustic signal and EMG of the internal and externalintercostals, the diaphragm and the abdominal muscles. Respiration tasks: normal, forced…, apnea List of 30 plurisyllabicwords, 40 non sensewords, 10 sentences varying in length and syntaxiccomplexity, and spontaneous speech. 15 repetitions, 2 speakers, standard french • Experimentconductedwithprofessors Jammes, Y and Grimmaud, Ch • atUniversityHospital La Timone in Marseille

44. General Theory of Co-ordinated Movement • Hoshiko (1960), Adam and Munro (1973), and Marchal (1988) reconsider the organization of muscular activity during speech. • For speech activity, the intercostal muscles and the diaphragm appear to act synergisticallyduring both the inhalation and exhalation phase. • The diaphragm has a role up from the start to the end of the exhalation involved in both speech and singing as hypothesized by Sundberg et al., 1999; Lindblom and Sundberg, 2005).

45. Control of respiration as a Co-ordinated Movement • Zinkin (1958): Diaphragm: control of the air supply and of subglottal air pressure. • Marchal (1988, p. 6) looks at the asynchronous peaks of activity in the diaphragm and the internal intercostals which he interprets as a response to the need to modify the supply of air according to the impedance of the larynx and the vocal tract.

46. EMG of the respiratory muscles during a speech task

47. Revised Model of the Control of Respiration Marchal observes asynchronous peaks of activity in the diaphragm and the intercostals during exhalation It appears that the curve of the diaphragm does not return in a linear way during phonation exhalation . The speed of the rise of the diaphragm varies according to the phonetic structure of the utterance. Hypothesis: a response to the need to modify the supply of air according to the impedance of the larynx and the vocal tract. These findings support Zinkin (1958), for whom the control of the phonatory air-supply is due to the controlled behavior of the diaphragm.

48. Linguistic Functions Pulmonary Initiation • Egressive airflow: most common process for the production of speech segments Respiratory activity and the syllables • Stetson’s (1951) : Syllables initiated by a contraction of the II , interrupted by contraction of the EI > ballistic pulses • Syllables delimited by alternating actions in the internal and external intercostals in delimiting syllables.

49. Linguistic Functions • Ladefoged (1962) disagreed with Stetson’s theory of the syllable. • Not supported by experimentally robust data. • Lebrun (1966) considers that muscular activity has been more inferred from observation of the ribcage movements than directly measured.

50. Respiration and the Syllable • Difficult to establish an unequivocal relationship between syllables and muscular activity. • (relationship: not systematic; differences between activity peaks and numbers of syllables) • Marchal (1988) has only been able to make such a connection for slow read speech (as in lists of words and nonsense words) and in syllables accentuated for phrasal emphasis.