09 - Upper Articulatory

Question 1

What are the 3 basic issues/problems in speech production?

Answer 1

units of speech
context effects
feedback mechanisms

Question 2

With units of speech, what are the 3 levels often used to represent speech production?

Answer 2

Multi-unit sequence
- word, breath group, articulatory phrase…

Prearticulatory representation
-syllables, phonemes, allophones…

Motor realization
-spatial targets, acoustic goal, vocal tract shape…

Question 3

What are the 4 types of models of speech production?

Answer 3

Motor Program Models 
Feedback Models 
Connectionist Models
Action Theory (Dynamic system) Models

Question 4

What are the 2 context effects (context sensitivity problem)?

Answer 4

Coarticulation - feature from one sound spreads into the articulation of an adjacent or earlier sound
-accounted for with “look ahead mechanism” in models

Suprasegmental/prosodic Effects

• loud vs soft
• stressed vs unstressed syllables
• slow vs fast
• clear vs casual

Question 5

Regarding the role of feedback mechanisms, what does closed loop vs open loop mean?

Answer 5

closed loop = feedback

open loop = no feedback

Question 6

What does “servomechanism” refer to?

Answer 6

Feedback about an error in the systems output is used to make a corrective change

Question 7

What is an important concern re. feedback mechanisms in speech (i.e why can’t they make an on-line correction to an error?)

Answer 7

Feedback signals are too slow

• moment-to-moment auditory feedback does not appear to be required for intelligible speech
• auditory feedback appears to be important for long-term maintenance of coordinated and intelligible speech

Question 8

Name 2 ways perturbations or distortions of auditory feedback can affect speech

Answer 8

Delayed Auditory Feedback (DAF) - can slow speech (50-150 ms used) and cause dysfluencies (200-400 ms used)

Masking Noise (Lombard Effect) - louder speech

Filtered Speech (i.e. Low pass filter) - higher pitch, decreased nasal

Altered Intensity or Pitch Shifted - speakers attempt to restore pitch or intensity

Question 9

Name 2 examples of how oral sensory feedback affects speech

Answer 9

Oral anaesthesia - minor effects

Trigeminal Sensory Neuropathy - permanent loss of oral sensory -> significant distortions

Perturbation responses - bite blocks are compensated for almost immediately

Question 10

What do feedforward mechanisms (or internal feedback) suggest?

Answer 10

Speech info re. motor commands are monitored directly or via parallel internal circuit, so errors detected and corrected rapidly

Question 11

What is a motor program?

Answer 11

• open loop control (no feedback)
• a plan or prescription for a movement or action
• makes no use of peripheral feedback (extreme form)
• less extreme models combine motor programs and feedback mechanisms

Question 12

What is schema theory?

Answer 12

• utilizes current sensory information and also previously learned relationships among movement outcomes, control signals, and initial conditions
• the schema are used to prepare and execute a motor program

Question 13

What does DIVA stand for?

Answer 13

Directions Into Velocities of Articulators

Question 14

What is the DIVA model?

Answer 14

A recent feedback model of speech motor control in which a feedforward control system (involving premotor and primary motor cortex, and cerebellum) works in concert with auditory and somatosensory feedback control systems that involve both sensory and motor cortical areas