assessment of hearing Flashcards
conductive mechanism
outer ear and middle ear
sensorineural mechanism
cochlea and auditory nerve and higher pathways
4 areas of concern that the case history presents
- past status of hearing
- present status of hearing
- estimate of prognosis
- etiology of hearing loss
otoscopy
provides illumination for examining the external auditory canal and tympanic membrane
portable audiometers
can only test pure tone air conduction and bone conduction
-cannot conduct speech testing
diagnostic audiometer
capable of producing pure tones, speech, and special audiometeric tests
-has a microphone for other tests
environment for testing
- standards set by the ANSI or ISO
- sound treated booth
bone conduction tests
bone oscillators are used -oscillator placed on mastoid bone -have to watch for vibrotactile responses -1000,2000,4000,500 Hz tells us the type of hearing loss
air conduction tests
-2 types of headphones
-supra-aural and insert headphones
tells us the degree or amount of hearing loss
supra-aural headphones
need to check for collapsing ear canals
- cheaper
- used if the ear is infected or if there is a malformation
- kids don’t want things going into their ear
insert headphones
- no collapsing canals
- greater noise suppression
- comfort when masking
- reduces signal crossover
conductive loss
pathology in the outer and middle ear.
air conduction thresholds will be elevated but bone conduction will be in normal limits
testing tips
- seat client facing away
- check for collapsing canals
- talk before- give directions
- red= right and left= blue
- before testing: take of glasses, client spit out gum/candy, etc
- always start the testing with their better ear
psychoacoustically pure tone threshold
lowest level at which a person gives a response 50% of the time
clinically pure tone thresholds
lowest level at which a person responds to a tone 3 times (in the ascending mode)
technique for testing
preparatory phase: begin at 30 dB HL or at a level in which the client can hear. decrease in 10 dB increments until you no longer get a response.
-then ascend in 5 dB steps until you get a response
-then drop down 10 dB until you get no response
-then ascend in 5 dB until you get a response
-repeat above sequence until you have the lowest level at which the person responded 3 times
CAN ONLY GET THRESHOLDS ON ASCENDING
air conduction testing frequencies
1000,2000,4000,8000,1000,500,250 -start with 1000 becasue its the easiest freq to percieeve and gives good test/retest reliabilty
bone conduction testing freq
250-4000 Hz
-dont test high freq bc the client will be more prone to a vibratory response
symbols for right ear
red o= right ear AC
red
symbols for left ear
blue x = left ear AC
blue > = left eat BC
blue square= left ear air masked
blue ] = left ear bone masked
4 categories for degree of hearing loss
mild, moderate, moderately severe, and profound
STUDY RANGES FOR EACH CATEGORY OF HEARING LOSS
slide 44
air-bone gap
difference of greater than 10 dB between air conduction thresholds and bone conduction thresholds
describes conductive and mixed losses
false positives
the person responds when there is no tone