Study Guide 2 Flashcards
What is “patterning” and why must it be avoided?
Presenting the tones at the same rate
people will click and you don’t know what they are responding to
how to avoid patterning?
mentally count in your head and count to a different number each time
what is the psychometric function?
basis for all threshold measures
how many times a patient will respond at 50% of the time but they can still respond above and below their threshold
probability of a response, 50% criteria
For pure tone testing?
What is the psychoacoustic method used?
How is starting level determined?
What is the step size?
What is the stopping rule?
How is threshold calculated?
method of presentation: adaptive staircase
starting level: at their threshold or 30
step size: down 10 up 5
stop rule? stop at 2/4 ascending
what is threshold: where we stopped
How do you test for test/re-test reliability? What is acceptable variation for a test to be considered reliable?
Air conduction (adult) ±5dB
Do this by rechecking 1,000 Hz
Start at 1,000, most sensitive frequency so it is easy to hear
Then test 1,000 2,3,4,6,8 and redo 1,000 to check for this reliability
if reliability is not in agreement If not in agreement want to find out why?
could not be answering honestly
Why would we get different results? They could’ve learned the test better, could have a really conservative response when starting, could be an equipment issue, audiologist could be patterning or marked it incorrectly.
Is it ok to note the lower threshold when testing for test/re-test reliability?
yes
list several factors that adversely affect pure tone test results
Patient observing dials
Incorrect adjustment of headband/earphone placement
Vague instructions
Patterning
Overly long test sessions
Examiner giving visual clues
Noise in test area
Stimulus presentations too long or too short
Identify important factors for soundfield testing.
Need to use a warble tone and no reflections and need to be seated under calibration sticker and seated the way the headphones were calibrated
If they were calibrated for 90 degrees azimuth they need to be seated with the speakers there
how do you report an audiometric test?
Pure tone air and bone conduction testing indicated/revealed hearing thresholds were within normal limits at both ears. Speech recognition thresholds (SRT) were in agreement with pure tone testing.
Pure tone air and bone conduction testing indicated/revealed hearing thresholds within normal limits at the right ear with mild sensorineural hearing loss at the left ear. Speech recognition thresholds (SRT) were in agreement with pure tone testing.
Pure tone air and bone conduction testing indicated bilateral high frequency sensorineural hearing loss. Speech recognition thresholds (SRT) were in agreement with pure tone testing.
Why are maximum permissible ambient sound pressure levels different for different transducers?
the inserts attenuate more sound (block) than the supra-aurals and the supra blocks more sound than not being covered
if there is a little sound and you have inserts in it will be ok but for bone conduction there cannot be noise in the background
why dont we use pulsed or steady tones for sound field?
so we can avoid standing waves
On an old audiometer, if signal is being sent to a headphone but you have them wearing inserts, what happens?
calibration is off
thresholds would be lower than what they have
List several disadvantages of supra-aural earphones
Possibility of a collapsed ear canal
Creation of an occlusion effect
Leakage of sound
Narrow frequency response (relative to
circumaurals)
Poor ambient noise attenuation
Awkward during bone conduction masking
List specifically when supra-aural earphones would be indicated
situations where insert earphones are contraindicated
structural abnormalities (atresia, stenosis)
a draining ear
presence of substantial cerumen
When are circumaural headphones required to be used?
extended high frequencies, have better noise attenuation than supras
List several advantages of insert earphones
Fit/comfort
Because the insert earphone uses a foam insert it can fit all but the most unusual (very small or very large) ear canals
Ambient noise attenuation
Better for masking
These benefits (other than comfort) are only present with proper placement (next slide)
What is the necessary insertion depth for insert earphones?
past the opening
Because it is calibrated based on the volume from the ™
What is the likely consequence of shallow insert insertion?
Elevated thresholds, especially in low frequencies
Masking benefits disappear
Explain how to interpret sound field testing results
The thresholds you get only pertain to the better ear and we don’t know about the other ear and we don’t know which ear is which based on sound field alone.
why do we not test bone above 4,000?
because of the response of the frequency of the bone oscillator
doesn’t transmit sound above 4,000 Hz
Why should you perform otoscopy yourself before placing transducers on a patient?
To ensure the ear canal is clear & normal appearing
Helps tell us if we need to use inserts vs supras, health of the ear, the shape of the canal, etc.
what is the occlusion effect?
Amount by which the threshold gets better when you plug the ear canal
Why should you place transducers on your patient rather than letting them do it?
Make sure it is accurately placed because it does matter, validity of test results
