Behavioral Audiometry

Question 1

What is classical (Pavlovian) conditioning?

Answer 1

• A response is elicited by the conditioned stimulus
  
  • EX: Pavlov conditioned a dog to salivate at the sound of a bell
• One can transfer the power of an unconditioned stimulus to a neutral stimulus to elicit a conditioned response (i.e. salivating)
• However, the power of the conditioned stimulus (bell) diminishes over time through repeated trials unless it is re-strengthened by occasional re-pairing with the unconditioned stimulus

Question 2

How was classical conditioning used in audiometric testing?

Answer 2

• In early development of behavioral pediatric audiology, psychogalvanic skin response (PSR) was used
  
  • Auditory stimulus (neutral) paired with electric shock (unconditioned stimulus) while measuring the amplitude and frequency of change in skin resistance (unconditioned response), so the power of the electric shock is transferred to the auditory stimulus
• Was used as an alternative to play audiometry (phased out of use after other measures were deemed more accurate, faster, and less traumatic)

Question 3

What is instrumental (operant) conditioning?

Answer 3

• A behavioral response elicited by a stimulus is controlled by the consequences of behavior
• Better approach to behavioral assessment of hearing in infants and young children

Question 4

Describe behavioral observation.

Answer 4

• Not considered appropriate for the estimation of hearing in infants under 5-6 months
  
  • High inter- and intra-subject variability
  • Rapid response habituation
• Useful to observe infant response to sound
  
  • Ensure general compatibility with other physiologic test results
    - Confirm parent/caregiver observations

Question 5

Why is “behavioral observation audiometry” considered an improper term?

Answer 5

-Audiologists cannot use behavioral procedures in the absence of reinforcement to estimate hearing sensitivity

Question 6

What is another name for visual reinforcement audiometry?

Answer 6

• Conditioned Orientation Reflex (COR)
• First described in 1961
• Required infant to orient to 1 of 2 sound sources prior to being rewarded with a visual reinforcer

Question 7

What is VRA?

Answer 7

• Coined to describe a similar procedure to COR that did not require localization for reward (i.e. VRA is a detection, not localization task)
• Auditory stimulus presented, infant turns head 90 degrees, then is presented with visual reinforcer

Question 8

What are some reinforcement options for VRA?

Answer 8

• Want a complex enough reinforcement to stave off habituation
• Social reinforcement
• Video VRA
• Animated toy

Question 9

Describe the VRA procedure.

Answer 9

• Train the response by pairing stimulus and reinforcer
• Start level should be close to threshold to increase efficiency and accuracy
  
  • Most babies will have normal/near normal hearing so 30 dB is okay
  • If moderate HL is present, increase by 20 dB
• After initial response is determined, 20 dB down/10 dB up
• Not appropriate to just screen at 20-25 dB HL (ideally want to find threshold)
• Obtain 2 responses (50%) at a specified level to stop at a given frequency
• Watch timing/insert control trials
• If child doesn’t show initial response, try to condition to a BC signal to provide tactile sensation
  
  • If conditions to that, he is “conditionable” and just can’t hear stimulus
    - If doesn’t condition, try electrophysiologic testing

Question 10

What is conditioned play audiometry?

Answer 10

• Should be used to test children at developmental age of 3 and “carefully selected” 2 year olds
• Selected behavior must be clearly defined as the behavioral response
  
  • Motor response must easily facilitate the procedure of operant conditioning and responding
• Response behavior must occur within 3 seconds after stimulus onset

Question 11

What are acceptable forms of reinforcement for CPA?

Answer 11

• Most common is social/verbal praise
  
  • Start with 100% reinforcement and then back down to intermittent
• “Peep show” of illuminated pictures
• “Movie screen”
• Picture reinforcement
• Slides that tell a story

Question 12

Describe the CPA procedure.

Answer 12

• AuD has child in a ready state and teaches him to respond
• If listener can’t respond to verbal instruction, modeling or hand-over-hand training can be employed
• Probe trials should be used to determine whether conditioning has been established
• Use similar Hughson-Westlake technique to that of VRA
• Include control trials