Pure Tone Audiometry Flashcards
why do we test hearing using pure tones?
- frequency specific thresholds
- type and severity of hearing loss
standard earphones
- proper placement is quick and easy
- easier and more comfortable for children
- inexpensive
insert earphones
- proper placement can be tricky
- children may not participate with fitting due to discomfort
- expensive
- better at reducing ambient noise during testing outside of a sound booth
air conduction audiometry
assessing the air conduction pathway which is how we hear normally
outer ear - middle ear - inner ear
threshold
the lowest decibel (dB) hearing level in which a person can hear a signal and respond
right ear air conduction symbol
O
left ear air conduction symbol
X
no response air conduction symbol
arrow attached to a symbol
ex: X with arrow
air conduction audiometry, methodology
- 250, 500, 1000, 2000, 4000, 8000 Hz
- begin in the right ear first (or better ear) at 30 dB and 1000 Hz
- followed by 2000, 4000, 8000 Hz
- repeat 1000 Hz
- then 500 and finally 250 Hz
air conduction methodology: no response?
continue in 10 dB steps until response
air conduction methodology: no response at starting level of 30 dB?
begin at 50 dB
when searching for threshold, you will use…
bracketing
- 10 down, 5 up
- consistent response 3 times at lowest intensity, that is threshold
degree of hearing loss: normal
-10-25 dB
degree of hearing loss: mild
26-40 dB
degree of hearing loss: moderate
41-55 dB
degree of hearing loss: moderately-severe
56-70 dB
degree of hearing loss: profound
91 dB and above
bone conduction hearing
we can bypass the outer and middle ear by stimulating the inner ear through vibration of the skull
components of bone conduction
- distortional
- inertial
- osseotympanic
distortional bone conduction
distortion of the skull activates structures of the inner ear
inertial bone conduction
distortion of the skull causes the ossicular chain to move and it lags behind skull movement due to inertia