Test 2 Flashcards
hearing assessment protocol
case history
otoscopy
tympanometry
otoacoustic emissions
audiometry (bone conductions, air conduction, speech)
peds case history questions
-did child pass newborn screening?
-family history?
-speech/language delay?
-developmental delay?
-what concerns do parents have with hearing/speech?
adult case history questions
-what brings you in?
-what issues day to day?
-family history?
-pertinent medical history? (cancer or viral infections)
transducers
headphones, inserts, bone oscillator used to test hearing
when to use different transducers
headphones: infection
inserts: collapsed canal or children
bone oscillator: placed on mastoid bone
otoscope
illuminates and magnifies ear canal and tympanic membrane
specula
goes on end of otoscope
children: 2 or 3 cm
adults: 4 or 5 cm
otoscopy
examination of ear using otoscope
patient seated with examiner at ear level, using finger to brace
tympanometry
examination used to test condition of middle ear, measuring mobility of tympanic membrane and ossicles
purpose: determine point and magnitude of greatest compliance of TM
tympanometry testing procedure
probe with 3 plastic tube creates air tight seal and emits pure tone of 226 Hz followed by positive and negative pressure in ear canal
tympanometer- measures TM compliance as pressure in canal is decreased
Type A tympanometry*
suggests normal ear function
point of greatest compliance is a 0daPa and curve is inverted V
Type As tympanometry*
curve shows same characteristics peak below .3
with normal ear pressure, peak is shallower than Type A, indicating stiffness
Type Ad tympanometry*
same curve as Type A but amplitude of curve is high
associated with flaccidity of TM or separation of ossicular chain
Type B tympanometry*
no peak pressure or compliance measure= flat line
caused by fluid in ear, PE tubes, perforation, or wax
Type C tympanometry*
peak pressure falls below normal, compliance is normal; indicates negative pressure in middle ear
peak is present, but shifted to negative side of the graph
acoustic reflex
contraction of the middle ear muscles in response to intense sounds which has the effect of stiffening the middle ear system and decreasing static acoustic compliance
threshold
softest level that an acoustic reflex is measured 50% of the time
responses obtained in ipsilateral and contralateral conditions
otoacoustic emissions
sound produces by activity of outer hair cells that can be measured in the external ear canal
types of otoacoustic emissions
spontaneous
transient evoked
distortion product
spontaneous otoacoustic emissions (SOAEs)
spontaneous and not evoked by sound stimulation
absent in some normal hearing people; recorded in 70% of normal ear, mostly females
transient evoked otoacoustic emissions (TEOAs)
elicited with a very brief sound presented at intensity level of 80dB SPL (sound pressure level) at 500-4000Hz
distortion product otoacoustic emissions (DPOAEs)
elicited with pairs of two pure tones usually at frequencies closely spaced together and presented simultaneously at 55-65 dB SPL at 500-8000 Hz
When two pure tones are presented to the ear, the outer hair cells (OHCs) in the cochlea generate sound waves at frequencies that are multiples of the original tones. These sound waves, known as distortion products, travel back up the ear canal and can be detected by a microphone.
When to use OAEs
with children who cannot sit for long periods of time and individuals with little trunk control (cerebral palsy, etc.)
as a screening tool for further evaluations
process of recording OAEs
probe inserted and will calibrate once test starts. DPOAEs activation follows simultaneous presentations of 2 different pure tone stimuli which activates outer hair cells and creates distortion product
you want a robust response above the noise floor
air conduction
sound goes through outer, middle, and inner ear
bone conduction
sound bypasses outer and middle ear and goes to inner ear
pure tone audiometry
measurement of hearing threshold for pure tones
audiometer
electronic device used to conduct hearing test
typically two channels (one for each ear) and comprised of buttons and dials
audiometry
hearing test procedure
what does pure air audiometry test?
frequencies 250-8000Hz; -10 to 110 dB
what does bone audiometry test?
frequency 250-4000Hz; -10 to 50d dB or 80 dB
air audiometry testing procedure
place earphone over ear or compress into canal
(red-right/blue-left) and instruct patient to press button each time they hear a tone/beep
air audiometry testing criteria
test 500, 1000, 2000, 4000
begin test at 1000Hz at 70 dB; if response obtained, move to 30dB and 20dB (if response obtained, patient passes frequency)
if no response at 20dB for 1000-4000Hz or no response at 30dB for 500Hz, patient fails screening
pure tone air conduction testing
ASHA ascending testing procedure
-test at 250, 500, 1000, 2000, 4000, and 8000 Hz
-begin at 30 dB at 1000 Hz
-if response is obtained: down 10 dB and up 5 dB
-if no response: increase by 5 dB until response, then down 10 dB, up 5 dB
how many times does a patient have to respond to find the pure tone air conduction threshold?
found when patient responds at the same level 3 times
pure tone air conduction average
average of 500 Hz, 1000 Hz, and 2000 Hz thresholds
speech audiometry
audiologist presents the word without the patient being able to read their lips in any way, and the patient repeats the word
speech detection threshold
(SDT) lowest level in decibels at which a patient can barely detect the presence of speech and identify it as speech
speech recognition threshold
(SRT) lowest level in decibels at which speech can be understood (50% of the words correctly identified)
uses spondee word list at 30dB, then down 10, up 5 dB
speech recognition threshold can be predicted by
pure tone average
and should be in agreement within 6dB
degrees of hearing loss
mild, moderate, severe, profound
configurations of hearing loss
used to describe how hearing thresholds change as a function of test frequency
3 common factors of configurations of hearing loss
flat, rising, sloping
flat configuration of hearing loss
hearing thresholds between any testing frequency does not exceed 15 dB difference
(essentially straight horizontal line)
rising configuration of hearing loss
features poorer thresholds in lower frequency rising to higher frequency
(diagonal low to high)
sloping configuration of hearing loss
features better thresholds in lower frequency to poorer in high frequency
types of hearing loss
conductive
sensorineural
mixed
conductive hearing loss
-caused by problem with outer and middle ear
-air conduction thresholds are abnormal, bone conductions thresholds are normal
sensorineural hearing loss
-caused by problem with inner ear or auditory nerve
-air and bone conduction thresholds are normal
mixed hearing loss
-caused by problems with a combination of outer, middle, and inner ear or auditory nerve
-some bone and air thresholds are normal and some are abnormal
