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Speech Production
SOMAYEH SHAHSAVARANI
90/1/29
Language
Speech
Painting
Language
Writing
Signing
Studying Methods
 Classical Methods (Invasive)
 Surgery Operation
 Modern Methods (Non-invasive)
 MRI
 FMRI
 PET-Scan (Positron Emission Tomography)
Speech
 Speech
 Speech Production
 Speech Perception
 Speech Signal Processing
Model Types
controller
 Old models
 The Traditional Locationist Model
Speech Production, Grammar: Broca’s Area
 Speech perception, Dictionary: Wernicke’s Area

 New Models
 Circuit Models

Speech Production: Broca’s Area, Basal Ganglia, Internal Capsule
(the nerve fibers that connect the neocortex to subcortical
structures)
Speech Production
Plant
Articulation
Phonation
Respiration
Speech Production
Plant
Plant
Speech Sounds
 The speech phonemes are generally divided into two
groups:

Vowels
The vowels are produced by open mouth
 The sound which is produced by vocal cords (vocal folds) vibration
is the source of vowels. The vocal tract that is located over the
vocal cords filters the sound. Different configurations of vocal tract
lead to different vowels.


Consonants
consonants are produced by nearly closed mouth
 Consonants are produced by the air passing through the oral cavity
and oral nasal. Different configurations of tongue, teeth and gum
lead to different consonants.

Fundamental Frequency and Formant
Frequencies
 Fundamental Frequency:
 Vowel sounds are produced by vocal cords vibrations. The
vibrations produce an alternating wave. Any alternating wave
has a fundamental frequency and a number of harmonics.
These harmonics are the integer multiples of the fundamental
frequency. The fundamental frequency of the alternating wave
produced by vocal cords vibration is related to vocal cords
vibration speed. For example, for a fundamental frequency,
100 Hz, vocal cords open and close 100 turns per a second. It is
important to be mentioned that the vowels are not
distinguished by fundamental frequency. A vowel may be
produced with different fundamental frequency. On the other
hand, at a specific frequency, some different vowels may be
produced.
Fundamental Frequency and Formant
Frequencies
 Formant Frequencies :

Different vowels are distinguishable by their formant
frequencies. The vocal tract which is located over the larynx
acts as a filter. It strengthens some harmonic frequencies and
attenuates some others. The harmonics which are
strengthened are called formant frequencies. Different vowels
have different formant frequencies.
Face Muscles
 The Muscle of Expression
 The Muscles of the Mouth
Orbicular Oris
 Levator Labii Superior and Alaeque Nasi
 Levator Labii Superior
 Depressor Labii Inferioris

 The Muscle of Mastication
 Temporal Muscle
 Masseter
 Medial Pterygoid
 Lateral Pterygoid
Production
Learning
Speech Motor
Development
 Speech production is a developmental process.
Speech Production Modeling
 Vocal Tract and Articulators Modeling
 Mass-Spring-Damper
 The Underlying Neural Basis of Speech Production
and Learning Modeling


Artificial Neural Networks
Model-Predictive Control
DIVA Model (2005)
 Directions In to Velocities of Articulators
Daliri Model (2007)
Kröger Model (2008)
Speech Production Learning
 Speech Acquisition


Auditory Feedback
Babbling phase
 Speech Motor Development

Somatosensory Feedback (Proprioceptive(Muscle Spindle) +
Tactile(Pressure-mechanoreceptors))
Coordination Development Between Articulators
 integrate new behaviors with previously stabilized ones
 Increase the control of individual articulator
 Articulators Movement Speed
 Decrease Performance Variability

Green Study
Three distinct developmental processes:
Integration
Differentiation
Refinement
Brain Areas in Speech Motor Control
 Premotor Cortex
 Supplementary Motor Area
 Primary Motor Cortex
 Somatosensory Cortex
 Supramarginal Gyrus
 Primary Auditory Cortex
 Higher-order Auditory Cortex
 Cerebellum
 Basal Ganglia
Brain Areas in Speech Motor Control
Supplementary Motor Cortex
Primary Motor Cortex
Somatosensory Cortex
Premotor Cortex
Supramarginal Gyrus
Higher-order Auditory
Cortex
Primary Auditory Cortex
Cerebellum
The Model of Integration Index During of
Speech Motor Development
Plant (Jaw/ Lower Lip)
n2
Force
F
1
  2
G 2
Displacement X ms  bs  k
s  2n s  n2
3857
H _ Jaw( s)  2
s  37.01s  372.4
H _ LowerLip ( s ) 
3000
s 2  15s  500
Controller
Artificial Neural Network
Quantitative Indices
 Contribution Index
One  year  old Two  year  old


0.65
0.5
 1
 2
0.27
0.32
Six  year  old
0.46
0.4
 Correlation Index
Adults 
0.43 
0.43 
Simulation Result
Prediction of the Model
In the unnatural conditions, if the connections between motor neurons in
brain stem did not develop properly for any reason, the correlation between
jaw and lower lip movement would fail. However, the lower lip’s contribution
is increasing while the jaw’s decreases.
Thank You