Speech science

Affricates

are consonant sounds that begin as stops and release as fricatives, resulting in a single sound produced with a complete closure followed by a turbulent release, such as the sounds in "ch" and "j".

How does coarticulation occur surrounding nasal consonants

the airflow is directed through the nasal cavity due to the lowering of the soft palate, allowing the oral cavity to remain closed, producing sounds like "m" and "n".

How does a nasometer work

Seperates the nasal vs oral sound pressure

What is a nasometer used for

Estimate the opening of the velopharyngeal port,Positive pressure and existence of airflow = open velopharyngeal port 

What is a pneumotachometer

Measures airflow and converts the pressure differences into an electrical signal

What is pneumotachometer used for

Estimating air volume in speech

Kinematics

Measures of position, velocity, and accelerationc

x-ray cineradiography

Video x-ray of speech that shows the full vocal tract. Exposure to radiation and hard to analyze.

Electromagnetic articulography

Precise tracking of articulators simultaneously, no radiation used

Electromagnetic articulography disadvantages

No measurement of the vocal tract, only shows mid-line, somewhat invasive

Dynamc MRI

Mid-saggital slice with fast sampling, good anatomical resolution of the vocal tract, non invasive

Dynamic MRI disadvantages

Only mid-saggital, data is hard to analyze and expensive

What does electropalatography measure and how does it work

Measures where the tongue makes contact with the palate for different sounds, giving real-time visual feedback. It works by using an acrylic palate that has electrodes that signal when the tongue touches it.

Rigid endoscopy

Used by the oral pathway and only shows vowels. Excellent images but uncomfortable

Flexible endoscopy

Usually used through the nasal and visualizes many speech sounds, giving a bird's-eye view of the velopharyngeal port. Quality a little lower

Electroglottograph

Measure the vocal fold contact area by placing electrodes on the neck at either side of the larynx and applying voltage. Vocal fold contact is recorded buy changes in electrical resistance

Methods to track breathing during speech

Respiratoru magnetometers and respiratory induction plethysmography

Segmental of speech

Vowels and consonants

Suprasegmentals of speech

Features of speech whose effects extend beyond individual speech sounds. (pitch, loudness, length)

Three main ways prosody is encoded

Pitch, loudness, and duration. prososdy carries linguistic meaning, but not phonetic contrast

Intonation contours

The shape of the contour conveys additional meaning about questions, emotions, and the end of the phrase

Lexical / word stress

stressed syllables put emphasis on certain syllables, higher pitch, louder, and longer

Prominence

The decision about how much stress to place on units, which can change the meaning of the sentence

How do speakers increase their speech rate?

Reduced pauses, centralized and reduced vowels, consonants and formant transitions are reduced, segment deletion

Clear speech

Speech produced in an effort to be highly intelligible. Slower, louder, avoids vowel centralization

Speech soud disorder

Difficulty with perception, motor production, or phonological representation of speech sound and segments

Organic SSD

Caused by hearing loss, atypical anatomy, neurological impairment

Fucntional SSD

Failure to use speech sounds appropriately for one’s developmental level with no explanation. Sound omission, substitution, distortions, usually to one or a few classes of sound.

Stuttering

Disruption in fluency from involuntary repetitions, prolongations, or silent blocks. 4x more common in boys. 75-80% recover

Dysarthria

A group of neurological disorders that show abnormailites in the strength, speed, range, steadiness, tone, or accuracy of movements needed for breathing, phonatory, resonatory, articulatory, and prosodic aspects of speech production.

Apraxia of speech

Sound prolongations, additions, distortions, substitutions, audible and visible groping for articulatory postures

Flaccid dysarthria

imprecise articulation, reduced intelligibility, difficulties coordinating speech breathing, and overall weakness. Lower motor neuron

Hypokinetic dysarthria

Reduced maximum vowel duration and loudness, loudness decay, breathiness, and reduced range of motion. Basal ganglia control circuit

Ataxic dysarthria

uncoordinated, slow, and irregular speech movements. "pa-ta-ka". Damage to the cerebellum

Vowel space for dysarthric speakers

Smaller due to centralized vowels, atypical formant frequencies, limited and slow articulater movements

MSD Perceptual methods

Standard for differential diagnoses. Decisions aboput progress and management may be inconsistant, unrelaible, and biased

MSD Acoustic methods

Uses speech samples and demonstrates perceptual judgement

MSD physiological methods

Investigate functions of speech directly, muscle activity (electromyography), movements of speech structures (articulography), timing, and coordination across systems.

Imaging methods MSD

common for swallowing, velopharyngeal, and laryngeal function (videofluroscopy, nasal endoscopy/laryngoscopy

canonical redupulicated babbling (6-7 months to 10 months)

Vocal tract closures release into the open vocal tract like CV syllables /da/. Often repetative /dadada/

Veriegated babbling (8-10 months)

Sounds have several articulatory closures or vowel like openings, usually with multisyllabic strings /daba/

Motor learning

A set of processes associated with practice or experience leading to relatively permanent changes in the capacity for movement. Critical to the treatment of MSD

Generalized motor program

Plan for a class of movements whicha can be scaled and specified to meet demands

Generalized motor program golf swing example

Same overall movement patter, but specific muscle parameters, durations, adn amplitued are specified as needed

Maas GMP

Predicts that trnasfer of learning will occur across place but not manner, or only within general motor programs

Distributed vs massed practice (PML)

Distributed

Variable vs constant practice (PML)

Variable

External or internal focus (PML)

External results in higher accuracy and reduced movement variability

Generalization/ transfer (PML)

transfer tends to be more from complex to simple movements

Theory

Used to bind and organize facts into an integrated frameowkr to allow for generalizations. Expalins what, why, and how. Is testable and falsifiable

Model

A simplified, idealized version of reality. Used to provide output to compare with data

Levelts process of phonological encoding

Assembling word forms (sound sequences) in preparation for speaking

Levelts process of phonetic encoding

Incremental preparing, selecting of articulatory gestures/ motor commands

Levelts process of articulation

Over extension of those motor commans resulting in movement and sounds

Degrees of freedom

The number of independently controllable elements in the speech system

Closed loop feedback control

Relies on output to correct and meet target

Feedforward control

Based on sensory feedback but then only rely on feedback to correct and detect errors

Velocities of articulators

Motor commands that change the vocal tract

DIVA targets

Speech targets are specified in the auditory

General purpose of DIVAS feedback control system

Uses erros sensed in auditory or somatosensory inuputs to correct outputs

General purpose of DIVAS feedforward control system

Executes commands with an open-loop approach, learned muscle activations for a well-practiced sound

Why can't DIVA (and real speakers) rely exclusively on auditory feedback control to guide speech production?

Too delayed to control the rapid complex movements for fluent speech