Speech Physiology

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Speech Physiology

• How human speech sounds are produced

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Basic events of speech production

• Initiation
• An activity that initiates the flow of air
• Phonation
• An activity that modulates the quality of sounds
• Articulation
• An activity that modulates or articulates the air
  stream

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Initiation

• Setting the airstream in motion
• Creating airstream is an essential process of
  sound production
• Change in pressure
• Three mechanisms of initiation
• Pulmonic airstream mechanism Lung
• Glottalic airstream mechanism Glottis
• Velaric airstream mechanism velum

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Three mechanisms (cntd.)

• Pulmonic
• Respiratory mechanism whereby a stream of air
  initiated by the lungs
• Most (more than 95) of human speech sounds are
  produced in this way
• Glottalic
• Oral closure
• Raise/lower larynx
• Release oral closure
• Air moves out/into the mouth
• Velaric
• Tongue-velum contact
• Anterior closure
• Drop tongue
• Air moves into the mouth

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Initiation (cntd.)Directions of airflow

• Egressive/pressure
• Exhalation deflation of lungs and consequent
  compression of the air
• Ingressive/suction
• Inhalation dilate the lungs, sucking air into
  the luns

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Phonation

• To produce speech sounds, air stream should be
  distorted in one way or another
• Phonation is a process of changing air stream
• Phonation is mainly achieved at larynx

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Larynx

• The upper portion of the windpipe which produces
  speech
• Major components
• Vocal cords
• Glottis
• epiglottis
• Three cartilages
• Thyroid, Arytenoid, Cricoid

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Larynx midsagittal view
Epiglottis
Thyroid cartilage
Arytenoid cartilage
Cricoid cartilage
Trachea
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Larynx lateral view
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Larynx posterior view
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Vocal cords
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Vocal Folds Vibration

• http//www.humnet.ucla.edu/humnet/linguistics/faci
  liti/demos/vocalfolds/vocalfolds.htm

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Articulation

• Contribution by organs to shape airflow
• A variety of speech sounds can be produced in
  terms of another way of air stream change
  Articulation
• Articulation is done mainly somewhere at vocal
  tract

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Vocal Tract

• The air passage above the larynx
• Its composed of
• Pharynx
• Oral Tract
• Nasal Tract
• Velic closure
• Active raising of velum preventing air from going
  out through the nose

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Articulators

• An specific part of the vocal apparatus involved
  in the production of a speech sound
• Active articulators
• Movable parts of the vocal apparatus
• Eg) lips, tongue, lower jaw, velum

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Articulator (Tongue)
Tip
Front
Centre
Back
?? Root
Blade