Behavioural Measures of Hearing

Question 1

BOA

Answer 1

Behavioural Observation Audiometry

• From birth
• presentation of noisemakers of a known frequency content to elicit a behavioural response
• requires two audiologists
• measured by sound level meter
• 0-6months respond above threshold
• can be used to rule out moderate/greater degrees of losses
• high face validitiy
• cannot pick unilateral losses
• looking for similar responses

Question 2

BOA set up

Answer 2

triangle or line - noise maker and SLM equidistant from baby

triangle possibly better so you can see SLM and baby response

Question 3

BOA stimulus parameters

Answer 3

Noisemakers include rattles, xylophone notes, horns, tambourines, bells, celllophane etc.

presented for 1+ seconds - long for pure tone sounds

interstimulus interval at least 10 seconds

stimulus 30cm from ear

vary stimulus to avoid habituation

need to include non-stimulus trials
- breeze, shadow, movement etc after every 3-4 presentations

Question 4

BOA infant state

Answer 4

Best state for the infant to be in is a very light sleep

the quieter the pre-stimulus state the greater the increase in activity on stimulus presentation

Question 5

BOA limitations

Answer 5

• Not very frequency specific
• Cannot obtain threshold
• Test of responsiveness, not absolute sensitivity
• Success depends upon the infant state and the experience of both the presenter and the observer