Test 2 Flashcards
(50 cards)
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
