The speech production process

True or false: most models of speech are a circular process

True

What are the five areas of speech production?

neural control system -> initiation -> phonation ->

articulation ->

perception

What is the role of the neural control system in speech production?

Recognise stimulus and fire signals to muscles involved in speech to formulate a response

Initiate action once plan is completed

What is the mechanism of initiation?

Provide the energy of speech by initating airflow that can be used as the energy of speech

What is the mechanism of phonation?

To transform the silent airflow into sound by the vibration of the vocal folds.

What is the mechanism of articulation?

To modify the shape of the vocal tract to create specific speech sounds.

Why is hearing relevant to speech production?

Provides feedback, high quality feedback optimises speech articles

What do delayed auditory feedback studies (DAFS) show and what is the relevance for SLTs?

DAFS show that the greater the delay of auditory input, the fewer no. of syllables per sec

forensics - some individuals used DAF devices to make insurance claims after accidents

Clinical - DAF devices can reduce stammers for some people

What are the functions of the Cortex in speech?

The external layer of the brain responsible for neural cognitive processing, including the planning and formulation of speech.

What is the function of the cerebellum in speech?

Optimiser of human activity e.g., movement of muscles to formulate speech

What are the primary functions of the right hemisphere?

The right hemisphere controls the left side of the body and is responsible for action and emotion.

What are the primary functions of the left hemisphere?

The left hemisphere controls the right side of the body and is responsible for logic, reason, and (for most individuals) language production and comprehension

What is the function of Broca's area?

Broca's area (located in posterior part of inferior frontal gyrus) is responsible for encoding or producing speech.

What can cause disfluency (AKA Broca's) aphasia?

Disfluency aphasia is caused by damage to Broca's area by e.g., stroke, inflammation, tumour, neurodegeneration, brain trauma.

What are the symptoms of disfluency (AKA Broca's) aphasia?

Poor language production (word-finding problems, agrammatism, and effortful speech) but relatively good language comprehension

What is the function of Wernicke's area?

Wernicke's area (located in posterior part of superior temporal gyrus) is responsible for decoding or comprehending speech.

What are the causes of Jargon (AKA Wernicke's) aphasia?

Wernicke's aphasia is caused by damage to this area e.g., stroke, inflammation, tumour, neurodegeneration, brain trauma.

What are the symptoms of Jargon (AKA Wernicke's) aphasia?

It results in poor language comprehension but fluent speech production, which is often difficult for others to understand

How does hearing provide feedback in speech production?

Hearing provides auditory feedback that allows a speaker to monitor and optimize their speech. Studies on delayed auditory feedback show that when this feedback is delayed, it can disrupt the speaker's rhythm and quality of speech.