PTA Niggly Bits Flashcards
What level should the ambient noise in the room not exceed?
35dB (A)
What 5 things should be asked before otoscopy?
Pain (otalgia), discharge, infections perforations opperations
What 3 things should be asked before PTA?
Loud noise exposure
Tinnitus
Better ear
How long should you torture patients before offering them a break?
20 mins
What points are important to emphasise when giving instructions
testing the QUIETEST sounds you can hear
press as SOON as you hear a tone no matter which SIDE
press when it STARTS and release when it FINISHES
Do you UNDERSTAND?
What order are you supposed to test frequencies in?
1000Hz - 2000 - 4000- 8000 then 500 and 250
Retest 1000 - shouldn’t be more than 5dB different - take more sensitive threshold
How should the tone be presented?
random timings between 1-3 seconds duration
to check for false positives
How is the patient familiarised with the task?
Present at 1000Hz tone at 40dB (norm hearing) or 30dB above predicted threshold
Define threshold in terms of PTA
the lowest level at which responses occur in at least half of a series of ASCENDING trials with a minimum of 2 responses required at that level
How is threshold determined?
Decrease level by 10 until no response occurs
Increase level by 5 until get a response
Decrease by 10 again until no response
Increase by 5 until get a response again… - threshold when respond at same level 50% of the time on ASCENDING (getting louder) trials
Placement of the bone vibrator
over mastoid prominance of worse hearing ear
1, 2, 4 then 500
Why it is important to occlude the test ear when testing 3000 and 4000Hz BC?
Because of air-borne radiation - the vibration from bone conductors can be heard and therefore influence b-c results at frequencies above 2000Hz
Why must the test ear not be occluded at frequencies below 3000?
Occlusion effect - artificially improve b-c thresholds
What type of masking noise should be used according to BSA 2011?
1) FRESH
2) Broadband
3) Warble
4) Narrow band
4
What is Rule 1?
Masking is needed at any frequency where the difference between the left and right not-masked a-c thresholds is 40dB or more
