Articulatory Theory

What is articulation?

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* Formation of speech sounds using the articulators
* Articulators
* Modify the sound wave
* Change resonance

What is the anatomy of the articulatory system?

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* Vocal tract → Bent tube
* Oral + nasal
* Mostly horizontal 
* Pharyngeal
* Mainly vertical 
* Shape is irregular and highly complex
* Variable 

What does the vocal tract consist of?

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* Pharynx 
* Oral Cavity
* Nasal Cavity

What are the mobile articulators?

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* Mobile
* Lips 
* Tongue 
* Velum (soft palate)

What are the immobile articulators?

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* immobile
* teeth
* alveolar ridge 
* hard palate

What does the oral cavity consist of?

* lips
* muscles
* mandible
* hard palate
* teeth
* soft palate/velum
* tongue

Oral Cavity - Lips

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* Bilabial sounds, facial expressions  

Oral Cavity - Muscles

* Orbicularis oris, elevators, depressors

Oral Cavity - Mandible

* Assists with bilabial production

Oral Cavity - Hard palate

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* Maxilla (anterior 3/4 ) 
* Palatine Bones
* Alveolars in addition to /sh, dz, and r/

Oral Cavity - Teeth

* Channel airflow, increase turbulence for /s/

Oral Cavity - Soft Palate/Velum

* Nasal, velar stops

Oral Cavity - Tongue

* main articulator

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__Muscles of the Velum (speech)__

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* Levator veli palatini
* Musculus uvulae
* Palatoglossus

What is the Levator veli palatini?

* primary elevator

What is the Musculus uvulae?

* Also elevates but tenses (bunches it up)

What is the palatoglossus?

* Depresses velum or elevates tongue

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__Variations in Velopharyngeal Closure__

* Coronal
* Sagittal
* Circular
* Circular with Passavant’s Ridge

Coronal

* Mostly velar, some lower pharyngeal wall (LPW)

Sagittal

* Mostly lower pharyngeal wall with small velar

Circular

* Equal contribution of both 

Circular with Passavant’s Ridge

* Movement of both with forward movement of the Passavant’s Pad on posterior pharyngeal wall

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__Parts of the Tongue__

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* Tip
* Blade
* Under alveolar ridge at rest
* Dorsum
* Broad superior surface 
* Body
* From tip to root

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* Tongue is __________, it can move in a variety of different ways 

flexible and fast

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* Modifies shape of oral cavity, which changes _________ as well
* **Most important articulator**

articulators

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__Muscles of the Tongue__

* Intrinsic 
* Extrinsic
* Elephant trunk example video 

What are the intrinsic muscles of the tongue?

* Change the shape of the tongue to produce articulation 
* Named for the direction the fibers run 

What are the extrinsic muscles of the tongue?

Change the position of the tongue to produce articulation 

What is the nasal cavity formed by?

many bones in the skull

What is the nasal cavity divided by?

nasal septum

* Each side has the inferior, middle, and superior conchae which help direct airflow

Why is the nasal cavity lined with cilia?

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* Filter
* Moisten
* Warm inhaled air 

What is the nasal cavity important for?

resonance of nasal sounds

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__Pharyngeal Cavity__

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* Important for resonance
* Constrictors change the shape of the tube 
* Superior may assist with channeling sound into the nasal cavity

What are the Valves of the Vocal Tract?

* labial
* lingual
* velopharyngeal
* laryngeal

What is the Labial valve of the vocal tract?

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* The lips may open and close dependent on the amount of air coming in and out of the oral cavity

What is the Lingual valve of the vocal tract?

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* Many points of contact for the tongue in the oral cavity
* Depending on where the tongue goes, airflow can be stopped or channeled. 

What is the Velopharyngeal valve of the vocal tract?

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* Walls differentiate where the airflow will go either through nasal or oral cavity 

What is the Laryngeal valve of the vocal tract?

* larynx

In Consonant Articulation, what are consonants involved in?

airflow obstruction

* Place - Voice - Manner (PVM)
* Most common way to describe consonants
* Changing place of the articulators to modify the airstream 

__Place of Articulation__

* Where a sound is produced

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* Bilabial 
* Labiodental 
* (inter-) dental/linguodental
* Alveolar
* Palatal
* Velar
* Glottal

What determines if voicing is occurring?

Whether the vocal folds vibrate when the sound is produced

__Manner of Articulation__

* How a sound is produced

* nasal
* stop
* fricative
* affricate
* approximant/semivowel

What is nasal?

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*  airflow through nasal passage (VP open) 

What is stop?

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*  obstruction of airflow

What is fricative?

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* constriction of airflow

What is affricate?

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* stop+fricative combination 

What is approximant/semivowel?

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*  narrowed vocal tract (liquids and glide) 

What do vowels involve?

* Articulation 
* Tongue height
* Tongue advancement
* Lip rounding 
* AE vowels are voiced 

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__Vocal Tract Resonance - Resonance__

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* Something set into forced vibration 

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__Vocal Tract Resonance - Acoustic resonator__

* Contains air that vibrates

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__Characteristics of the Vocal Tract as a Resonator__

* ¼ wave resonator
* Males 17-18 cm
* Females 14-15 cm 
* Young children 7-8 cm 
* Series of connected air-filled containers (oral, nasal, pharyngeal) 
* Broadly tuned resonator 
* Variable resonator 
* Every time the articulators move, the frequencies change 

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What is the ¼ wave resonator?

lowest resonant frequency has a wavelength that is 4 times/length of the tube

What are the resonant frequencies of the vocal tract?

formants

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* Higher formants are ____ number multiples of the lowest formant 
* x3,x5, etc

odd

In formants

* Typically only the first 3 are considered in _____
* F1, F2, F3

speech 

In formants

* Remember: ______________ are whole number multiples of the fundamental (250, 500, 750) 

F0 and harmonics

In formants

* F0 and harmonics are _______________ by the formats

dampened or amplified

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__Source Filter Theory - Vowels__

* Fant 1960s
* Speech sounds are the result of an energy source (acoustic energy from larynx) being filtered (by the vocal tract) 

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__Source Filter Theory__

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* Describes speech production as a two stage process involving the generation of a sound source, with its own spectral shape and spectral fine structure, which is then shaped or filtered by the resonant properties of the vocal tract. 

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__Formant Frequencies/Volumes or Oral and Pharyngeal Cavities__

* When producing schwa, cavities in the front and back are equal in size
* Containers of a large volume will respond to lower frequencies and vice versa
* F1 pharyngeal volume (how big) and tightness of constriction, F2 oral length (how long)
* Vary by tongue height and tongue advancement
* Independent of VF vibration 

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__Vowel Formant Frequencies - changed via__

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* Length of the vocal tract
* Location of constriction 
* Degree of constriction 

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__Vowel Formant Frequencies - F1 associated with constriction__

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* High vowels - low F1
* Low vowels, high F1

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__Vowel Formant Frequencies -__ F2 associated with tongue advancement

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* Back vowels, low F2
* Front vowels, high F2

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__Vowel Formant Frequencies -__ F1 and F2 rules do not apply for _______ vowels

central

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__Age and Gender Differences - Young children__ 

* Corner vowels established at young ages
* Gender differences begin at age 4

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__Age and Gender Differences - Males__

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* Sharp drop in F1/F2 for corner vowels around age 15 

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__Age and Gender Differences - Females__

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* Increase in vowel space for low vowels only 

Spectrograms

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* Vowel acoustics
* From spectrogram to spectrogram 
* Everything from the source filter and putting it on a graph 
* Including all formants  (black portions of the spectrogram shows increased amplitude)
* F3 related to lip rounding 
* Monophthongs and Diphthongs (F2 changes mostly) 

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__Nasals on a Spectrogram__

* Nasals - acoustics 
* Murmur 
* Nasal formant and anti-formant produced
* A filter that is filtering out other sounds 

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__Semi Vowels__

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* Articulation - narrowing of vocal tract
* Acoustics - like vowels
* We, you (glides) 
* Like, row (liquids)
* Resembles a formant transition 

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__Liquids__

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* Steady state formants
* /r/ Dependent on production 
* /l/ produces antiformants 
* F2 highly dependent on vowels surrounding it

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__Glides__

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* Low F1
* Rise to following vowel 
* F2 and F3 also shift to vowel 

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__Stops - Articulation__

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* Obstruction of airflow
* Pat, Bat
* Tab, Desk
* Cat, Grab

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__Stops - Acoustics - Silence__

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* Building up pressure 
* Voiceless - initial position likely not present
* Voiced - “voice bar” low frequency before vertical bar
* Medial/final in voiceless = silence 

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__Stops - Acoustics - Burst/Aspiration__

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* High frequency vertical bar 
* Voiceless stops longer in duration than voiced

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__Stops - Acoustics - Voice onset time__

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* Right before the voicing begins
* Will look different depending on voiced vs. voiceless sounds
* Prevoicing - voicing starts before release - voiced
* Simultaneous - happens at the time of the release -voiced 
* Short Duration - onset occurs after release - voiced 

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__Stops - Acoustics - Formant Transitions__

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* Moving from constriction to more open position of a vowel 

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__Stops - Acoustics - F1__

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* = low (high degree of constriction)

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__Stops - Acoustics - F2__

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* = low for bilabials 
* Alveolar mid range (\~1800 Hz)
* Velar varies dependent on vowel 

F1

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* Tongue height
* Volume of pharyngeal cavity
* Degree of constriction 

F2

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* Tongue advancement
* Location of Constriction
* Length of the oral cavity in front of the constriction

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__Fricatives - Acoustics__

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* Noise
* Hard to define the sounds of fricatives which leads to little distinction on the spectrogram 
* Fricatives → relates to size of cavity in front 
* Voiced vs voiceless 
* Voice bar at low frequencies for voiced 

Coarticulation

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* Speech sounds vary within context due to overlapping articulation in fluent speech 
* Forward articulation - /kip/ = slight fronting of /k/ in anticipation of more front sounds
* Backward articulation - /mi/ = nasalization of /i/

What are Suprasegmentals?

* intonation
* stress
* duration

* intonation

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* - the way we vary out F0 to convey different types of messages (declarative, interrogatory) 

* stress

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* - varying frequency, intensity, and duration of a word that highlights a specific portion
* Word stress
* Sentence stress 

* duration

* length of a speech sound

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__Articulation Applications__

* spectrograms and beyond
* MRI
* Electropalatography and Glossometry
* Electromagnetic Articulography
* Acoustic Analysis
* Hearing Impairment
* Cochlear Implants
* Treatment

MRI

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* = magnetic resonance imaging
* Good for sustained vowels to measure the position of the vocal tract

Electropalatography and Glossometry

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* Custom palate created with electrodes to measure tongue movement (even small changes
* Visual display for most sounds (glossometry) and those with tongue-palate contact (EPG)

Electromagnetic Articulography

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* Electromagnetic Articulography

Acoustic Analysis

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* Visipitch, Praat for visual feedback 

Hearing Impairment

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* Speech characteristics of listeners with profound hearing loss
* Reduced auditory feedback
* Vowel neutralization 
* Consonant omissions, substitutions (P/V/M)
* Inappropriate suprasegmental features

Cochlear Implants

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* Improved access to auditory input does not always translate to improved articulation 
* However, after implantation
* Improved vowel production/spacing
* Better outcomes when implanted earlier

Treatment

* Use of spectrograms for visual feedback, particularly on vowels and increasing overall output
* EPG used for improving articulatory production
* Provides visual feedback of movement of the articulators
* Can be used with and without traditional articulation therapy

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__Speech Sound Disorders__

articulation

phonological process

productive knowledge

acoustic analysis knowledge

Articulation

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* sound substitutions, omissions, or distortions

Phonological process

 patterns of errors (fronting, final consonant deletion)

Productive knowledge

does the child perceive the sound and produce it in a way that may be imperceptible to a listener

Acoustic analysis

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* important for evaluating individual differences that may not be perceptible and expected progress in therapy. Also important for discrimination in therapy