1. SPPA 6010 Advanced Speech Science
Phonation
SPPA 6010 Advanced Speech Science

2. Laryngeal Activity in Speech/Song
Sound source to excite the vocal tract
Voice
Whisper
Prosody
Fundamental frequency (F0) variation
Amplitude variation
Realization of phonetic goals
Voicing
Devoicing
Glottal frication (//, //)
Glottal stop (//)
Aspiration
Para-linguistic and extra-linguistic roles
Transmit affect
Speaker identity
SPPA 6010 Advanced Speech Science

3. SPPA 6010 Advanced Speech Science
Topic Sequence
Basic Laryngeal Anatomy
Myoelastic-aerodynamic theory of phonation
Basic Features of Phonation
Frequency and Intensity Control
Other Phonatory Parameters
Instrumentation
SPPA 6010 Advanced Speech Science

4. SPPA 6010 Advanced Speech Science
Behrman Chapter 5, 6
Place less emphasis on…
Minor anatomical landmarks and features
Extrinsic muscles of the larynx
Blood supply to the larynx
Central motor control of larynx
Peripheral Sensory control of larynx
Stress-Strain Properties of Vocal Folds
SPPA 6010 Advanced Speech Science

5. SPPA 6010 Advanced Speech Science
Location of Larynx
SPPA 6010 Advanced Speech Science

6. SPPA 6010 Advanced Speech Science
Bones
Hyoid Bone
Key Cartilages
Thyroid cartilage
Cricoid cartilage
Epiglottis
Arytenoid cartilages
SPPA 6010 Advanced Speech Science

7. SPPA 6010 Advanced Speech Science
Cricoarytenoid Joint
Cricothyroid Joint
SPPA 6010 Advanced Speech Science

8. SPPA 6010 Advanced Speech Science

9. SPPA 6010 Advanced Speech Science
Key structures
esophagus
posterior
arytenoid
glottis
Pyriform sinus
True vocal fold
aryepiglottic fold
False (ventricular) fold
epiglottis
anterior
SPPA 6010 Advanced Speech Science

10. Intrinsic Laryngeal muscles
Key Actions
Adduct
Abduct
Tense
Slacken
Lengthen
Shorten
ADDUCTION
not
independent
of each other
ABDUCTION
SPPA 6010 Advanced Speech Science

11. Intrinsic Laryngeal muscles
Lateral cricoarytenoid (LCA)
(Inter)arytenoid (IA)
Posterior cricoarytenoid (PCA)
Thyroarytenoid (TA)
Cricothyroid (CT)
Principal Actions
Adducts
Abducts
Shorten/slack-tense
Lengthen/tenses
SPPA 6010 Advanced Speech Science

12. Extrinsic/Supplementary muscles
Suprahyoid muscles
Digastric
Mylohyoid
Geniohyoid
Stylohyoid
Infrahyoid muscles
Thyrohyoid
Sternothyroid
Sternohyoid
Omohyoid
SPPA 6010 Advanced Speech Science

13. Extrinsic/supplementary muscles
Holds the larynx in the neck
Allows positional change of the larynx
Elevates when swallowing
Elevates during certain speech activities
Elevating pitch
High vowel production
SPPA 6010 Advanced Speech Science

14. SPPA 6010 Advanced Speech Science

15. SPPA 6010 Advanced Speech Science
Layers of Vocal Fold
Cover
epithelium
superficial layer (Reinke’s space)
Transition Area
intermediate layer
deep layer
Body
TA muscle
Lamina
Propria
(LP)
vocal ligament
SPPA 6010 Advanced Speech Science

16. The vocal fold through life…
Newborns
No layered structure of LP
LP loose and pliable
Children
Vocal ligament appears 1-4 yrs
3-layered LP is not clear until 15 yrs
Old age
Superficial layer becomes edematous & thicker
Thinning of intermediate layer and thickening of deep layer
Changes in LP more pronounced in men
Muscle atrophy
SPPA 6010 Advanced Speech Science

17. SPPA 6010 Advanced Speech Science
Topic Sequence
Basic Laryngeal Anatomy
Myoelastic-aerodynamic theory of phonation
Basic Features of Phonation
Frequency and Intensity Control
Other Phonatory Parameters
Instrumentation
SPPA 6010 Advanced Speech Science

18. Myoelastic Aerodynamic Theory of Phonation
Necessary and Sufficient Conditions
Vocal Folds are adducted (Adduction)
Vocal Folds are tensed (Longitudinal Tension)
Presence of Aerodynamic pressures
SPPA 6010 Advanced Speech Science

19. 2-mass model Upper part of vocal fold Mechanical coupling stiffness
Lower part of vocal fold
Coupling between
mucosa & muscle
TA muscle

20. SPPA 6010 Advanced Speech Science
VF adducted & tensed → myoelastic pressure (Pme )
Glottis is closed
subglottal air pressure (Psg) ↑
Psg ~ 8-10 cm H20, Psg > Pme
L and R M1 separate
Transglottal airflow (Utg) = 0
As M1 separates, M2 follows due to
mechanical coupling stiffness
Psg > Pme
glottis begins to open
Psg > Patm therefore Utg > 0
SPPA 6010 Advanced Speech Science

21. SPPA 6010 Advanced Speech Science
Utg ↑ ↑ since glottal aperature << tracheal circumference
Utg ↑ Ptg ↓ due to
Bernoulli effect
Pressure drop across the glottis
Bernoulli’s Law
P + ½ U2 = K
where
P = air pressure
 = air density
U = air velocity
SPPA 6010 Advanced Speech Science

22. SPPA 6010 Advanced Speech Science
Utg ↑ Ptg ↓ due to Bernoulli effect
Ptg < Pme
M1 returns to midline
M2 follows M1 due to
mechanical coupling stiffness
Utg = 0
Pattern repeats times a second
SPPA 6010 Advanced Speech Science

23. SPPA 6010 Advanced Speech Science

24. Limitations of this simple model
Actual VF movement is more complex
Vocal folds have length and vary in biomechanical properties along their length
SPPA 6010 Advanced Speech Science

25. Complexity of vocal fold vibration
Vertical phase difference
Longitudinal phase difference
SPPA 6010 Advanced Speech Science

26. SPPA 6010 Advanced Speech Science
Vibratory Complexity
SPPA 6010 Advanced Speech Science

27. SPPA 6010 Advanced Speech Science
Topic Sequence
Basic Laryngeal Anatomy
Myoelastic-aerodynamic theory of phonation
Basic Features of Phonation
Frequency and Intensity Control
Other Phonatory Parameters
Instrumentation
SPPA 6010 Advanced Speech Science

28. SPPA 6010 Advanced Speech Science
Glottal area waveform
SPPA 6010 Advanced Speech Science

29. SPPA 6010 Advanced Speech Science
Flow Glottogram
SPPA 6010 Advanced Speech Science

30. Phonatory Behavior: Aerodynamic Features
Volume Velocity
Driving Pressure
Laryngeal Airway Resistance
Phonation Threshold Pressure
Initiate phonation
Sustain phonation
SPPA 6010 Advanced Speech Science

31. Acoustic consequence of vocal fold vibration
Air disturbance is caused by the “slapping” together of the vocal folds
Sound energy is maximum at glottic closure
Given the complexity of the vibratory patterns of the vocal fold, the sound produced at the glottis is complex and periodic.
SPPA 6010 Advanced Speech Science

32. Glottal waveform (Time domain)
‘triangular’ shaped
Looks simple, but is complex
SPPA 6010 Advanced Speech Science

33. Glottal waveform (Frequency domain)
Harmonics have a 12 dB/octave roll off
SPPA 6010 Advanced Speech Science

34. The real deal: Phonation is actually quasi-periodic
Contains two components
Periodic
Complex periodic
Harmonic structure
12 dB/octave roll off
Aperiodic
Broad frequency noise embedded in signal
SPPA 6010 Advanced Speech Science

35. Sources of aperiodicity
Non-periodic vocal fold oscillation
Inappropriate combination of Psg and Pme
Mucosal disease, neuromuscular disease, poor fluid balance, etc
Asymmetry of vocal fold oscillation
Anatomical asymmetry
Unilateral paralysis/paresis, mucosal lesion,
Air turbulence due to
Open phase
Incomplete glottal closure
SPPA 6010 Advanced Speech Science

36. SPPA 6010 Advanced Speech Science
Voicing vs. Whispering
SPPA 6010 Advanced Speech Science