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SOMAYEH SHAHSAVARANI
90/1 /29
Speech Production
Language
Language
Speech
SigningWriting
Painting
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 Typescontroller
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 ProductionPlant
Articulation
Phonation
Respiration
Speech ProductionPlant
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
Speech Production Learning
Speech production is a developmental process.
Speech Motor Development
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: IntegrationDifferentiationRefinement
Brain Areas in Speech Motor Control
Premotor CortexSupplementary Motor AreaPrimary Motor CortexSomatosensory CortexSupramarginal GyrusPrimary Auditory CortexHigher-order Auditory CortexCerebellumBasal Ganglia
Brain Areas in Speech Motor Control
Premotor Cortex
Supplementary Motor Cortex
Primary Motor Cortex
Somatosensory Cortex
Supramarginal Gyrus
Primary Auditory Cortex
Higher-order Auditory Cortex
Cerebellum
The Model of Integration Index During ofSpeech Motor Development
Plant (Jaw/ Lower Lip)
2
2 2 2
1
2n
n n
Force FG
Displacement X ms bs k s s
2
3857_ ( )
37.01 372.4H Jaw s
s s
2
3000_ ( )
15 500H LowerLip s
s s
ControllerArtificial Neural Network
Quantitative Indices
Contribution Index
Correlation Index
1
2
0.65 0.5 0.46 0.43
0.27 0.32 0.4 0.43
One year old Two year old Six year old Adults
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