audiogram interpretation - exam 2 Flashcards
clinical threshold procedure
yes –> decrease by 10dB
no –> increase by 5dB
repeat until response to 2/3 ascending presentation
description of HL
degree: how much HL
configuration: what is the shape of the HL
type: what type / where is the HL
symmetry: what is the difference between ears
stability: what is the time course of the hearing loss
degree
various ways of defining
most common is thresholds, specifically AC thresholds because sound is typically heard through the air
normal hearing
-10 - 25
mild hearing loss
26-40
moderate hearing loss
41-55
moderately severe hearing loss
56-70
severe hearing loss
71-90
profound hearing loss
> 91
pure tone average
provides rough estimate about degree of HL
useful for predicting thresholds for speech audiometry
3 freq: 500, 1000, 2000
4 freq: 500, 1000, 2000, 4000
why use 4 freq PTA
for a sloping hearing loss in the high freqs
3 freq PTA wouldn’t show that
configuration of hearing loss
combined w/ degree of hearing loss to describe how the hearing loss changes across freq
configuration types
flat
sloping - most common
precipitously sloping - very steep slope usually between 1-4kHz, relatively flat before that
rising
cookie bite
reverse cookie bite
notch - normal everywhere, pointed notch (usually around 3-4kHz)
normal hearing type
AC & BC withing -10-25 dB across all freqs
conductive hearing loss
BC normal hearing
AC worse
ABG >= 10
issue in the MIDDLE EAR
sensorineural hearing loss
AC & BC both outside normal range (>25)
ABG< 10
issue in INNEREAR
mixed hearing loss
AC & BC both outside the normal range (>25)
AC worse than BC
ABG >= 10
issue in MIDDLE EAR & INNER EAR
bilateral symetry
hearing loss is similar between ears
<= 15dB
unilateral symmetry
hearing loss is only in one ear
other ear has normal hearing
asymmetrical
degree &/or configuration are different between ears at 3 freqs in a row
(>15 dB)
stability
change over time (between audiograms)
requires having more than one audiogram
stable
no significant change over time
(<= 10)
progressive
hearing loss becomes worse over time
(>10 change)
common
sudden
more than 30dB change at at least 3 freqs in less than 72 hours
don’t really know the cause
fluctuating
hearing loss changes over time
sometimes improves, sometimes worsens
very rare
can BC thresholds be higher (worse) than AC thresholds?
in an ideal world: no, AC won’t work if inner ear doesn’t work
BC = inner ear doesn’t work
in practice: yes, because it is a behavioral test
