exam 2 Flashcards
SRT
(stimulus type, open vs. closed, word lists, etc)
also when/how to mask
- speech recognition threshold
- spondee
- closed set
- no carrier phrase required
- visual cues are only ok in the familiarization stage
- patient is familiarized with test items
- MLV or recorded presentation
- ## recorded in dB HL
- masking: when the SRT of the test ear, minus the best bone conduction of the non test ear (from 500-4000 hz) is greater than interaural attenuation
- ——SRTte - best BCnte >/= IA
- level: start 15 db above the SRT of the NTE, then find a plateau
SAT or SDT
(stimulus type, open vs. closed, word lists, etc)
- speech detection/awareness threshold
- cold running speech
- open/closed set and carrier phrase don’t apply
- patient not familiarized with test items
- presentation is MLV or recorded
- recorded in dB HL
QuickSin
(stimulus type, open vs. closed, word lists, etc)
- quick signal in noise
- sentences in noise at different SNRs
- open set
- no carrier phrase required
- patient is not familiarized with test items
- recored in SNR loss (the db separation requried bewteen signal and noise)
WRS (or SDS/SRS)
- word recognition score / speech discrimination score (CID-22 or NU-6)
- PB lists monosyllabic words
- open set
- carrier phrase is required
- patient is not faimilarized with test items
- presentation: recorded
- ## recorded with % correct, test, & number present
- masking is always needed if it is for SRT
- mask if the presentation level is more than the interaural attentuation above the best BC of the NTE
- level: set level (no threshold search)
- —-for up to a mild HL: SRT + 40
- —-for anything over a mild HL: UCL - 5
tympanogram type A
normal peak compliance (.2-1.6) and pressure (-125–+125)
- can have sensory/neural loss
tympanogram type As
normal pressure but reduced compliance (<.2)
- s= stiff (small peak)
- can occur with: immobolized ossicles; thick TM; begining or end of an ear infection
type Ad tympanogram
normal pressure but excessive compliance (>1.6)
- can occur with: flaccid ear drums; separation of ossicles
type B tympanogram
no peak at any pressure (check if ecv is normal-> .5-2.0)
- smaller ecv: bony portion blocked with cerumen
- normal ecv: middle ear full of infected fluid
- larger ecv: eardrum with a hole in it
type C tympanogram
normal compliance but negative peak pressure (< -125)
- end of an ear infection
- eustachian tube dysfunction
- allergies, congetsion, ET blocked
reflex arc for right ipsilateral and contralateral ART pathway
- ipsilateral: stimulus in right ear-> RIE (inner ear)-> RVIII (auditory nerve)-> RCN (cochlear nucleus)-> RSOC (superior olivary complex)&VII(facial nerve) nucleus-> RVII-> R acoustic relfex-> probe in right ear
- contralateral: stimulus in right ear-> RIE-> RVIII-> RCN-> LSOC&VII nuclues-> LVII-> left acoustic reflex-> probe in left ear
what may produce an absent/elevated response vs a normal response?
(in an ART)
ie. acoustic reflex threshold
- absent= not present at the highest level (115 dB HL on audsim)
- elevated= 100
- possible causes:
- middle ear problem
- 60 db hl or worse cochlear hearing loss
- damage to auditory nerve or facial nerve
1. the ear with the probe assembly must not have any outer or middle ear pathology
2. the ear with the stimulus must recieve a tone that is loud enough
3. the neural pathway must be adequate to activate the contraction of the stapedius
- normal ART are in the range 70-95 db hl
- we also expect them to be at 70-90 db SL (referencing the pure tone threshold) ->can’t really interpret hem until after we find pta
- possible causes:
mild to moderate cochlear hearing loss (30-60 db hl)-> with cochlear loss, acoustic reflexes occur at reduced sensation levels (<70 db hl)
what are the hearing loss configurations?
flat, sloping, rising, cookie bite, precipitous/steeply sloping, corner, noise notch
always describe from least loss to worst, unless it is rising then worst to least
degrees of hearing loss and dB HL levels they occur at
normal: -10-25
slight (KIDS ONLY): 16-25
mild: 26-40
moderate: 41-55
moderate/severe: 56-70
severe: 71-90
profound: 91+
what does “VT” mean on an audiogram next to a bone conduction threshold?
vibrotactile response (felt rather than heard)
what is an SOAE
spontaneous otoacoustic emission: continuous tonal signals that occur without any stimulation–present in about 50% of normal ears (if they have them they prob have a normal iner ear and middle ear)
- a person may have multiple SOAEs at different frequencies
- not used clinically
what are EOAEs
otoacoustic emissions that are produced in response to an acoustic stimulus
- two kinds that are used by clinical audiologists: transient and distortion product
what is a TEOAE ?
how is it tested/what stimuli is used to evoke it
transient evoked otoacoustic emissions
- 2 choices of evoking stimuli (called transient becuase it is a very short stimulus- but lots of them)
- —-clicks (broad band)
- —-tone pips (very brief pure tones
- in a single test, several hundred stimuli are presented in rapid succession-> what the ear produces in response:
- —–a broadband sound (ie contains energy over a broad frequency range)
what is a DPOAE?
what is the evoking stimuli and how are they measured
what is the response?
distortion product otoacousstic emissions
- evoking stimuli: two steady pure tones, presented simultaneously
- —called primaries with frequencies F1 and F2
- F1 is always taller and F2 is always higher pitched
- relationship between F1 and F2 is preset to maximize test sensitivity
- in a single test, the primaries will sweep through the whole audiometric frequency range
response:
- several pure tones, all mathematically related to the primaries (called distortion products)
- primary levels & frequencies are chosen to maximize the imission at 2F1-F2
example: F1= 1000 Hz; F2=1200 Hz–> F(dp)= 800Hz
what is a DP-gram
plot of DPOAE levels as a function of F2 frequency
- each point on x-axis reflects the functional status of a specific region of the cochlea
- you want a big separation between the nosie floor and the response (should be at least 6dB greater than the noise- ie SNR)
- SNR required to pass: 6 dB or greater for at least 75% of frrequencies
what is eletrocochleography (EcoG)
measurement of the earliest evoked potentials (changes in brain acitvity in response to specific stimuli) that come from the cochlea
what is ABR and what does it test?
the auditory brainstem response is an EEG based waveform with several peaks and troughs that are produced by electrical potentials recorded from neural generators in teh brainstem in response to a click or tone burst
- can tell us funcitoning all the way up to the brainstem
- patient has to be still and the room can’t have lots of electricity (because it could interfere with the test)
what waves to we look at when measuring an ABR
(auditory brainstem response)
- wave I: distal portion of VIII cranial nerve
- wave II: proximal part of VIII cranial nerve
- wave III: superior auditory complex
- wave IV: hits pons and lateral lemniscus
- wave V: midbrain, lateral lemniscus, and inferior colliculus
explain latencies and amplitudes (in relation to ABR) and how we interpret/use them
- latency: the timing of a response relative to the stimulus (in other words: the time at which a particular wave on the response occured)
- —the response that has the widest clinical application is the auditory brainstem response (ABR)
ABR occurs in the first 10 ms after the stimulus
- generated by the auditory nerve and auditory brainstem
- thus, normal ABR implies normal cochlea
- different types of latencies: absolute, interpeak, interaural
- amplitudes: individual wave amplitudes
- —amplitude ration between wave V and wave I -> V/I ratio: wave five should always be bigger
what is EHDI?
early hearing detection & intervention
- OAEs then automated ABR (AABR) if infant does not pass
- AABR is preferred for babies in the NICU
what are the 3 components of early hearing detection & intervention programs?
1-3-6
- birth admission screening (by 1 month)
- follow-up screen & diagnostic (diagnosis by 3 months)
- early intervention (intervention by 6 months)
these are the longest acceptable times
what should an audiological assessment include for babies up to 6 months ?
- child and family history
- tone-burst ABR to determine degree and configuration of hearing loss (gives frequency specific information)
- click ABR to assess brainstem function
- OAEs
- tympanometry using 1000 Hz probe tone
- behavioral observation audiometry (BOA)
what is VRA?
what ages is it used for, when can it be used
visual reinforcement audiometry
- used for corrected age of 6 months to 2.5-3 years (need to be able to turn head to look at sound)
- child is seated between and in front of loudspeakers
- each speaker holds a visual reinforcement within the child’s peripheral vision
- condition the child, when a sound comes-the reward somes at the same time, so then when you play the sound they will look for the reward
what is CPA?
what ages is it used for, when can it be used
conditioned play audiometry
- ages 3-5
- taught by demonstration
- when they hear a tone they will add a puzzle piece or move a block or something
- —–it is a game for the child, may need to physically show them, remind them that they are listening, could use a listening posture to help
what does success depend on in conditioned play audiometry (CPA)?
- motivataion (have multiple listening games ready for when they get bored)
- contiguity (make sure the tone is what is cueing them to respond)
- generalization across freq & intensity
- descrimination
- reinforcement (even more than the even, clap/praise them)
what are the 6 walls of the middle ear box model
- lateral/membranous
- medial/labyrinthine
- superior/tegmental
- inferior/jugular
- posterior/mastoid
- anterior/carotid
lateral/membranous wall
- tympanic membrane
- epitympanic recess
- chorda tympani
medial/labyrinthine wall
- oval window
- cochlear promontory
- round window
- facial nerve canal
- portion of lateral semicircular canal
superior/tegmental wall
- tegmental plate
inferior/jugular wall
- tympanic plate of the temporal bone
posterior/mastoid wall
- aditus ad antrum
- pyramidal eminence
anterior/carotid wall
- tendon of the tensor tympani muscle
- orifice of the eustachian tube
ossicles
- 3 smallest bones in the body
- suspended in the middle ear cavity by ligaments
- ossiculra chain: malleus, incus, stapes
what are the 3 purposes of the middle ear?
- transduction
- impedance matching
- pressure equalization
explain the transduction function of the middle ear
plz
- ME converts acoustic energy to mechanical energy
- tympanic membrane is a heavily damped sympathetic vibrator
- tm vibrations propagate through ossicular chain
- stapes movement in oval window sets inner ear fluids into motion
describe the impedance matching function of the middle ear
to overcome energy loss as sound travels from air-filled middle ear to fluid-filled cochlea
ME has several mechanisms for increasing sound pressure
- area ratio increases energy 17-fold
- ossicle level action ups energy by factor of 1.3
- total energy increase: 23.1 or about 30 dB
- increase in sound pressure = gain
what is transfer function of the middle ear
transfer function is a plot of gain as a function of frequency
- we see that middle ear gain is frequency-dependent
otitis media
eustachian tube disorder with a patulous eustachian tube
- not what we usually mean when we say “eustachian tube disorder”
- when the cartilagionous portion stays open
- mostly just annoying to the patient
- head in a barrel feeling, breathing and chewing noises, autophony
how to diagnose a patulous eustachian tube?
with a tympanometer, watch for middle ear compliance changes as the patient breathes
- put probe in the problem ear and plug opposite nostril
- bending over can often hlep with the pressure
what is eustachian tube dysfunction
and its causes and effects
when the cartilaginous portion won’t open
- what we usually mean by etd
- causes:
1. edema (swelling)
2. overgrown adenoids
3. structural abnormalities
- effect: negative middle ear pressure
what is negative middle ear pressure and its effects
- results from eustachian tube dysfunction
- mucous membranes absorbs the air in the middle ear
- tympanic membrane becomes retracted, even atelectic
audiological effects:
- type c tympanogram
- mild conductive hearing loss, if any
what is a cholesteatoma
a pseudotumor in the middle ear
- composed of skin, keratin, fats
- starts when skin cells enter middle ear
- usually associated with chronic OM and with perforated and retracted TMs
(pars flaccida retraction pocket is a common site)
- can consume whole attic and middle ear
- very destructive (eats away at ossicles, tegmen tympani, tm, etc)
effects and treatment of a cholesteatoma
- conductive hearing loss, type B tymp
- will often cause pain, facial nerve symptoms (can spread to pharynx or brain)
treatment: surgery 100% of the time - then monitored for rest of life bc they often regrow
- mostly with surgery hearing won’t be improved and htey will often end up getting hearing aids
what is otosclerosis
abnormal growth of spongy bone tissue over the footplate of the stapes (interferes with movement of the stapes)
- hereditary in 70% of cases
- more frequent in women than men (usually first noticed during 20s–will worsen during pregnancy)
effects and treatment of otosclerosis
progressive, conductive hearing loss
- starts in low frequencies (increased stiffness)
- eventually, we see flat moderate conductive hearing loss, with type As tymp
- carhart notch: depressed bone conduction threshold at 2000 hz (arises form disruption of inertial bone conduction)
- sensorineural component as disease progresses into cochlea “cochlear otosclerosis”
-acoustic reflexes are always absent
- can’t localize well or understand people in loud environments
treatment: surgery called stapendectomy
- stapes is removed, graft is used to seal the oval window, stapedial prosthesis (95% successful)
hearing aids: people with conductive hearing loss tend ot be extremely successful hearing aid users
otitis media (generally)
- bilateral, unilateral, or viral infection of the middle ear
- 2nd most common illness of childhood- most common disorder of the middle ear
- causes a conductive hearing loss
- can cause serous effion of the middle ear (when me becomes a vacuum-fluid of blood is being sucked into the middle ear)
se of me is treated iwth pe tubes
don’t use antibiotics for serous effusion of the middle ear because it is not infected
electrocochleography
measurements of the earliest responses that come from the cochlea
