Quiz 3 (Speech Perception, Immittance Testing) Flashcards
What’s important to remember about speech audiometry terminology?
it’s rarely agreed upon by all, varies from region to region
What do we need to perform speech perception testing?
a DIAGNOSTIC audiometer
3 portions of a diagnostic audiometer that are important for speech perception testing
- CD system to play recorded material
- microphone for monitored live voice (MLV) testing
- VU meter: ensures that all speech is being presented at the exact same intensity
In speech audiometry, the patient must ____ and be able to ____
- know, respond to the word in the language of the test
types of responses possible by patients in speech audiometry and advantages/disadvantages of each
spoken
- advantages: faster, rapport between client/clinician
- disadv: client can have fairly unintelligible speech
written
- advantages: takes out guessing associated with a pt w/ poor speech
- disadv: slower, have to score it
clinician’s role in speech audiometry (3)
- must be able to convey to pt their task
- keep face from pt’s view
- understand pt responses
3 measures you can get from speech perception testing
- speech recognition threshold
- speech detection threshold
- word recognition scores
MLV is ______, however ____. So?
- easier and more flexible
- it’s not as accurate
- recorded speech is best to use
when testing with recorded speech ____ tone is provided. what do you do with it?
1000 Hz
- balance calibration tone on VU meter at 0
when testing using lvie voice testing, you must?
adjust microphone sensitivity to have the speech balanced at 0 dB on VU meter
define speech recognition threshold
lowest hearing level at which 50% of presented words are correctly identified
SRT should be in agreement with ____ by _____
PTA, +/- 10 dB
If SRT and PTA are not in agreeance, what could be the reason for this?
- testing error (e.g., equipment not calibrated)
- false info (e.g., difficult for listener to tell how loud/soft sound is)
In finding the SRT, it’s very important to do what?
familiarize the clients with the words using 9 or 10 words
KNOW how to find SRT
slides 12-15
In SRT, the stimulus is called _____. What’s important to remember about this? Examples include?
- a spondee (a word with 2 syllables, both syllables pronounced with equal stress and effort, each half will peak the VU meter at 0 equally)
- cowboy, baseball, cook book, ear drum
closed set vs open set in SRT? (?)
don’t know
Explain what speech detection threshold is
- is it typical?
- lowest hearing level at which a patient can barely detect the presence of speech. No understanding the word is involved. Simply, “I heard it”
- not typically conducted
when would we use SDT?
- a child who can’t repeat back words or point to a pic
- person with so significant a hearing loss that it becomes painfully loud if we turn it up too much
- stroke victims who can’t point or speak
difference between speech discrimination testing and word recognition testing
- word recognition tests person’s ability to understand the word, while detection only wants to know if they detect a sound or not
- hearing vs. understanding
word recognition scores
- a ____ test
- what’s this mean?
- suprathreshold
- given above threshold at a comfortable loudness level
word recognition scores provide? (2)
- info on real word speech communication function
- assists in dx of endocochlear pathology
in word recognition testing, stimuli are ____ and ____
- monosyllabic
- phonemically balanced
word recognition testing typically involves a _____
- example
carrier phrase
- Say the word ____
with WRS, present word ____ above SRT
- test each ____
- 40 dBSL
- ear
with WRS, make sure the volume unit?
peaks at 0 for all words
how to score WRS?
calculate percentage correct and record
how many words are typically in a phonemically balanced list used in WRS?
25 to 50
word recognition score aka?
speech discrimination score (?)
reasons for doing suprathreshold test (WRS)?
- gives info on whether a hearing aid will be beneficial
- gives ability to look at different air patterns in speech recognition
interpretation of WRS scores
- 100% = excellent = little to no difficulty understanding speech
- 80 to 99% = good = little to no difficulty understanding speech
- 60 to 79% = fair = occasional difficulty
- 45 to 59% = poor to fair = moderate difficulty
- 0 to 44% = poor = difficulty following convo
If you suspect ____, conduct ____
- what does this do?
- what will it tell us?
- retrochoclear pathology, high intensity WRS
- this taxes the nerve
- If WRS degrades at high intensity, this is known as ROLLOVER = indicative of ret. pathology
(WRS gets worse the higher the intensity gets)
importance of dynamic range for hearing aid use
- if a person has a very small dynamic range, then you can only amplify the sound a little bit before they say it’s too loud
what is MCL?
- most comfortable listening level
- listener rates where listening is most comfortable
why are MCL levels valuable?
- inter-test reliability
- reference for recognition/discrimination testing
- indicatory for narrow dynamic range
- helpful for hearing aid fitting
UCL = ?
- aka?
uncomfortable listening level
- loudness discomfort level (LDL)
- threshold of discomfort (TD)
why are UCL levels valuable?
- inter-test reliability
- indicatory for narrow dynamic range
- use in hearing aid fitting
- lower w/ people who have sensorineural hearing loss
Masking for SRT and WRS
- Compare presentation level of the ____ to the ____.
- If exceeds ____, add masking
- test ear, nontest ear bone threshold
- IA (interaural attenuation)
Make sure that no ____ is happening during speech perception testing
lip reading
tests that give a measure of a person’s sensitivity to sound across the frequency range important for speech communication
pure tone air conduction and bone conduction
test that gives a measure of the person’s sensitivity to speech
SRT
test that gives a measure of how clear speech is for a person when it is loud enough for them to hear
WRS
What does the outer ear include?
- auricle/pinna
- external auditory meatus
- tympanic membrane
do all disorders of the auricle result in hearing loss?
NO
most common congenital malformations of the pinna
microtia and atresia
what is microtia? impact on hearing?
- abnormally small pinna
- results in hearing loss only if there’s something secondary to it
what is anotia? impact on hearing?
- a missing pinna/auricle
- won’t result in hearing loss if ear canal is intact
Microtia and anotia are both considered ____ and _____
- craniofacial abnormalities
- non-syndromic hearing losses
non-syndromic hearing losses account for about ___% of all forms of inherited hearing loss
70
microtia and anotia - is surgery possible?
yes, can get a prosthetic
what is aural atresia? can affect? can be in ___ or ____?
- absences of an ear canal
- one or both of the ear canals
- isolation or with other abnormalities
aural atresia impact on hearing?
conductive hearing loss
aural atresia is common in who?
- people with Treacher Collins syndrome (inherited condition, issues with facial bones)
- people with Goldin Har syndrome (rare congenital defect where you have incomplete formation of ears, palate, mandible)
what is stenosis?
very small or narrow ear canal
list the disorders of the external auditory meatus
- aural atresia
- otis externa
- collapsing ear canals
- impacted cerumen
list the disorders of the auricle
- aural microtia
- aural anotia
what is otis externa?
- can be?
- one of most common types?
- why could there be issues with performing a hearing test?
inflammation or infection of the external auditory meatus
- fungal, viral, or bacterial
- swimmer’s ear
- because the pressure is so painful
impact of otis externa on hearing?
can cause a conductive loss if the pressure is great enough to cut off the ear canal
collapsing ear canals: more of a ___ than a _____
- really important when testing who?
condition, disorder
- children under age 7 and older adults
what is impacted cerumen?
a buildup of cerumen in the ear canal
who is susceptible to impacted cerumen?
- people who wear ear plugs all the time
- people with small canals (petite adults)
impact of impacted cerumen on hearing?
- varies depending on the amount of blockage
what may impact cerumen?
cleaning ears with Q-tip
notes to get from Ky:
slide 8 on disorders PP
slide 23 on disorders PP
list disorders of the tympanic membrane
atelectasis, perforation, tympanosclerosis/myringoclerosis
what is atelectasis
- see when?
- ear drum sucked backwards due to negative pressure in the middle ear space
- when eustachian tube isn’t working
possible causes of a TM perforation
- excessive pressure from middle ear infections, trauma (loud noises), forceful changing in air pressure (flying, diving and coming up too quickly, powerful sneeze)
does a perforation heal? explain
- sometimes it heals on its own. Tissue migrates over toward perforation.
- if it doesn’t spontaneously close or heal itself, then something is put over ear canal to allow it to heal
impact of perforation on hearing
- depending on size, can produce a mild to moderate conductive hearing loss
- larger the perforation, greater the hearing loss
what is tympanosclerosis?
scaring of the ear drum
- thickens/adds mass to the ear drum, calcium plaque gives ear drum a white chalky appearance
impact of tympanosclerosis on hearing?
- scaring in and of itself doesn’t result in hearing loss, but if it’s thick enough, then it can cause a conductive loss
list disorders of the middle ear
- otis media
- cholesteatoma
- otosclerosis
- ossicular disarticulation
number one disorder of the middle ear
otitis media
explain what otitis media is
- eustachian tube fails to open for various reasons
- negative pressure develops in middle ear
- mucous cannot drain (fluid)
what can cause the eustachian tube dysfunction seen in otitis media?
- structural issues (tonsils too large)
- swelling from infection (upper resp infection)
number one cause of otitis media in children
upper respiratory infections
in children, eustachian tube is more ____. So?
horizontal and angled
- won’t drain out as easily as adult
otitis media can be classified in what 2 ways?
- based on duration/frequency
- based on type of fluid (effusion)
ways to classify otitis media based on duration/frequency
- acute: single bout that lasts less than one month
- chronic: lasts longer than 2 mo
- recurrent: 3 or more acute episodes w/in a 6 mo period
if a kiddo has chronic or recurrent otitis media, make sure you look at?
speech and language developement
ways to classify otitis media based on type of effusion
- explain each
- serous: thin, watery, sterile fluid w/ no bacteria in it
- purulent: contains puss, bacteria. Signs may include fever, conductive hearing loss
sometimes, individuals with ___ otitis media may have no signs/symptoms at all
purulent
what does serous and purulent fluid look like?
- serious: clear and watery looking. Fluid bubbles visible through TM.
- purulent: mostly yellow fluid
a population who’s extremely prone to otitis media?
children with down syndrome
why are children more susceptible to OM?
- adults have more vertical ET
- adults have more cartilage support
% of kids who will have at least one episode of otitis media by age 6?
75-95%
what causes an earache?
- negative air pressure inside the middle ear causes TM to retract and stretch
- earache is in ear canal
otitis media impact on hearing
- conductive hearing loss that ranges from 15 dbHL to 45 dbHL
what else can otitis media cause?
TM perforation
is conductive loss usually permanent with otitis media?
NO
greatest amount of loss with otitis media is in the ____ frequencies
low
degree of loss with otitis media is dependent on?
- amount of fluid
If left untreated, what can otitis media lead to?
- ossicular erosion: ossicles erode bc they are sitting in fluid
- mastoiditis: infection of mastoid bone bc of fluid. untreated can lead to meningitis, possibly death.
- cholesteatoma
children with a history of otitis media before age 2 and a HL of 26 dB or greater - loss in ?
verbal ability, reading, math, language
where are PE tubes placed? how long do they stay there?
ear drum
- 6 to 12 months
what is a myringotomy?
incision into ear drum to relieve pressure or drain fluid
what is a cholesteatoma?
- characteristics?
a cyst/benign growth that appears as a large white mass behind the TM
- capable of reabsorbing bone that’s adjacent to it
- will be a foul smelling infection
what is otosclerosis?
- what does it result in?
fixation of the stapes into the oval window
- fluid in ear doesn’t move effiiciently. doesn’t match impedance of air fluid
Otosclerosis has a ____ component
- explain
genetic
- more common in females
- usually happens in 20s, associated with pregnancy
- usually occurs bilaterally
how do you treat otosclerosis?
- via a surgical procedure called a stapedectomy. Surgeon frees stapes, removes it from ossicular chain and replaces it with a prosthetic one that allows the ossicles to function again.
explain the audiogram of someone with otosclerosis in-depth
VERY TELLING
- conductive loss until 2,000 Hz. Suddenly a bone gap, called Carhart’s notch.
Telling symptoms of otosclerosis
- bluish tinge to white portion of eyes
- schwarts sign: flamingo pink/red TM
- paracusis willsii: say they can hear and understand speech better in noise
what is ossicular disarticulation?
break in ossicular chain
common cause of ossicular disarticulation?
- Closed head injury, trauma, especially if it’s related to temporal bone
impact of ossicular disarticulation on hearing
- major conductive hearing loss between 30-60 dB
- ossicular disarticulation interrupts?
- often times, in conjunction with?
- if this happens?
- the normal flow of energy from the air filled middle ear to the fluid filled inner ear
- tear in TM
- hearing loss can be substantial and disabling
often see ossicular disarticulation in who?
people in military, especially soldier who’ve been exposed to loud sounds/bombs, etc.
surgery that helps form new ossicular chain in ossicular disarticulation?
ossicular reconstuction
3 categories of disorders of the inner ear
- prenatal disorders
- perinatal disorders
- postnatal disorders
disorders of inner ear result in hearing loss that’s usually ____ in nature
sensorineural
prenatal disorders of inner ear
- syndromes and inherited disorders
- maternal infections
perinatal disorders of inner ear
- prematurity
- anozia
postnatal disorders of inner ear
- meningitis
- autoimmune diseases
- meniere’s disease
- ototoxicity
- noise induced
- presbycusis
explain major differences between conductive and sensorineural hearing losses
CONDUCTIVE
- usually temporary
- can usually be treated medically or surgically
- simply reduces the volume of the signal
- maximum loss of 60 dB
SENSORINEURAL
- usually permanent
- usually cannot be treated medically or surgically
- reduces volume of signal AND reduces clarity of signal (i.e., reduced frequency resolution)
- can range from mild to profound
2 most common causes of sensorineural hearing loss in adults
- noise exposure
2. aging
what is tinnitus?
ringing/buzzing in the ear that only the patient can hear
tinnitus is associated with?
conductive and sensorineural hearing loss
tinnitus can cause? explain
severe distress of it’s severe
- some patients will go to extreme measures to stop it (ex/ get auditory nerve snipped)
is tinnitus a disorder?
NO - it’s a symptom of a hearing loss
unilateral tinnitus?
red flag that it could be an 8th nerve tumor
amount of people that tinnitus affects
1/5
objective tinnitus?
doctor can hear it too, extremely rare, caused by a blood vessel problem
if a hearing loss is in combination with other symptoms, it’s referred to as?
a syndrome
congenital infections are often associated with what?
sensorineural hearing loss
maternal infections can result in? most damaging portion of pregnancy?
- sensorineural hearing loss
- first trimester bc cochlea is developing during 6-12 weeks
maternal infections that can cause hearing loss
- CMV
- toxoplasmosis
- rubella
most common cause of congenital hearing loss?
cytomeglovirus (CMV)
characteristics of CMV
- caused by a herpes-like virus that’s often symptomless for mom
- no vaccine
characteristics of toxoplasmosis
- parasitic infection due to raw meats, cat feces
- mom often won’t have symptoms, but will affect baby
characteristics of rubella
- viral cause
- last epidemic was in the 60s. vaccine created in 1969. people are now refusing vaccinations for different reasons, so there’s more of an outbreak now
some of the common acquired viral infections that can cause hearing loss
- herpes zoster oticus (what causes hearing loss), mumps (if accompanied by encephalitis), syphillis (usually occurs in secondary or tertiary stage of disease
often prematurity is accompanied by? which can lead to? and cause?
- hyperbilirubemia (JAUNDICE: too much billirubin, made when body breaks down RBCs)
- kernicterus: too much billirubin in blood cause brain damage, which can lead to hearing loss
how can anoxia affect hearing?
- lack of oxygen
- affects cells in brain and inner ear most often
- usually related to trauma during labor or delivery
what is meningitis?
- impact on hearing?
infection of meninges (protective layer of brain and SC)
- usually results in complete deafness
with meningitis, why must a cochlear implant candidate take quick action?
- bony cochlear duct fills with puss. As healing takes place, membranes replaced by bone. SO when a kid has meningitis, needs to immediately get a cochlear implant before cochlea fills with bone
- what are autoimmune diseases?
- affect on hearing?
- treatment?
- when body produces antibodies against its own tissues
- extent ranges from mild to severe. SUDDEN hearing loss (wake up and can’t hear). usually BILATERAL.
- steroids. If treated right away, hearing sometimes comes back
characteristics of ideopathic hearing loss
- sensorineural
- sudden, unilateral hearing loss
- no known cause
- usually accompanied by tinnitus
What is meniere’s disease?
oversecretion of endolymph in the scala media
- reisner’s membrane ruptures, massive amount of fluid
symptoms of meniere’s disease
- most common symptom: roaring tinnitus
- vertigo
- aural fullness
- FLUCTUATING UNILATERAL sensorineural hearing loss
- poor speech discrimination
- hearing loss in low frequencies
treatment for meniere’s disease?
steroids (anti-inflammatory), then insert a shunt to remove some endolymph
what does a typical audiogram for someone with meniere’s disease look like?
see slide 47
what medications are toxic to hair cells?
- chemotherapy (cisplatin, carboplatin)
- antibiotics (gentamycin, streptomycin)
- megadoses of aspirin, nicotine, diuretics
symptoms of ototoxicity include
- bilateral HIGH FREQUENCY sensorineural hearing loss
- tinnitus
regularly test someone’s hearing who’s on _____
- how?
chemotherapy
- start testing at 16,000 Hz and work way down because high frequencies are lost
characteristics of noise induced hearing loss
- lose high intensity sounds
- noise notch (3000-6000 Hz), loss of these frequencies = MAJOR SIGN
explain the different threshold shifts in a noise induced hearing loss
- temporary threshold shift: ex/ after a concert, don’t hear as well for a few days, then you’re back to normal
- permanent threshold shift: ex/ irreversible hearing loss from noise exposure
OSHA regulations to prevent noise induced loss?
85 dBA for an 8 hour day
noise induced hearing loss occurs more often in?
males, cuz they’re typically exposed to noise more often than females
why can exercising lead to noise induced hearing loss?
leads to decreased blood to cochlea, so you’ll turn up your music so you can hear
motorcycles occur at what dB?
93 dBA
see audiogram for noise induced hearing loss
slide 51
effect of noise is _____. explain
accumulative: dependent on frequency, duration of exposure, intensity, and individual
type of hearing loss rifle shooters have?
unilateral noise-induced loss
list some hearing protection devices
earmuffs, earplugs, musician’s earplugs
what is presbycusis?
auditory system structures degenerate with age
characteristics of presbycusis?
- percentage of population with this?
- bilateral high frequency sloping to sensorineural that occurs with advancing age
- poor speech discrim (lose CLARITY as well as intensity and volume)
- 25-40% over age 65
- 90% in 9th decade of life
list disorders of the central auditory system
- acoustic neuroma (8th nerve)
- auditory neuropathy (8th nerve)
- auditory processing disorder (beyond 8th nerve)
what is an acoustic neuroma?
- what type of disorder is it?
a benign tumor on the 8th nerve
- it’s slow growing and varies in size from person to person
- retrocochlear
5 symptoms of an acoustic neuroma
- unilateral tinnitus
- unilateral high frequency sensorineural hearing loss (because these freq. are coded on the outside of the nerve)
- speech understanding is usually REALLY poor
- vertigo
- abnormal auditory adaptation (abnormally high - audibility decreases rapidly)
why do acoustic neuromas occur?
no one really knows
what often comes along with acoustic neuroma?
a headache
how can you diagnose an acoustic neuroma?
- ABR, MRI, CT
neurofibromastosis and its link to an acoustic neuroma
neurofibromastosis: genetic disorder that causes tumors to grow in the nervous system
- could cause an acoustic neuroma
what is auditory neuropathy?
- explain
OHCs are fine, but IHCs, 8th nerve, and lower auditory BS is abnormal
- sound is going through, but not in a correct way. doesn’t enter nerve, brain, etc. in a correct way
will hearing aids help with auditory neuropathy? why?
NO - because increasing intensity can’t fix the wrong functioning
symptoms of auditory neuropathy
- mild to moderate sensorineural HL
- VERY POOR speech recognition abilities
what will diagnostic testing reveal with an auditory neuropathy?
- OAEs are present (cochlea is functioning fine)
- ABR (neural results) will be poor
why will an auditory neuropathy often go undiagnosed?
because audiologists don’t typically perform ABR on kids
what could help with auditory neuropathy? but?
cochlear implantation
- usually not suggested unless hearing is very poor
children with auditory neuropathy?
will often have resulting speech and language issues
- often need to supplement with cued speech or another visual
what is auditory processing disorder?
breakdown in the ability to interpret speech that’s due to issues in the central auditory nervous system
site of lesion for APD
- almost any area of the central auditory system
symptoms of APD
not a typical pattern, depends on where breakdown occurs
- most common:
- normal hearing (AC and BC normal), but they’ll act like they have a hearing loss
- difficulty when there’s background noise
- difficulty paying attn when there are distractions
- ask for repetitions
- difficulty understanding sarcasm
- often confused with LPD or ADHD
is there a “pathology” with APD?
NO - no tumor or anything
what will diagnostic testing show with APD?
- normal audiogram
- excellent word recognition in quiet
main spot in brain for processing speech in humans
left temporal lobe (heschl’s gyrus)
speech that’s directed to right ear goes?
directly to dominant contralateral left temporal lobe
order of transmission of sound through the nervous system
see slide 59
- auditory nerve
- cochlear nucleus
- superior olivary complex
- lateral lemniscus
- inferior colliculus
- medial geniculate body
- auditory cortex
give the 4 definitions of deaf
- Social: auditory/verbal communication is impossible or nearly imposible
- Medico-legal: avg threshold at 500, 1k, 2k is over 90 dB
- Educational: primary mode of learning is not auditory
- Cultural: written with a capital “D” - people who communicate with ASL consider themselves a minority group, not a handicapped person
difference between deaf and hard of hearing? are they mutually exclusive?
- HOH can function in hearing loss. Listen through auditory and communicate through verbal
- Deaf cannot appropriately function in hearing world (?)
- YES
- communication modality for deaf?
- educational placement for deaf?
- ASL, signed/cued speech, total communication
- self-contained or mainstreamed with interpreter
educational placement for hard of hearing?
- self-contained, mainstreamed, mainstreamed with interpreter, mainstreamed with hearing aid
what’s an organic hearing loss?
hearing loss that has an anatomical, physiological, or metabolic etiology
what’s a functional hearing loss? most common?
person presents with a hearing loss, but organic etiology is unknown. not consistent with clinical or audiological eval
- faking it?
- most common = teenage girls wanting attention
What are OAEs? Present when?
low level sounds generated by the motile respose of OHCs (when OHCs elongate and contract)
- when OHCs are healthy (not present when OHCs are damaged)
OAEs are recorded where using a sensitive microphone?
in the external ear canal
OAEs are really good for?
catching someone who is faking a hearing loss (a malingerer)
OAEs will be absent with what type of losses?
- conductive hearing loss
- sensorineural loss (?)
- who hypothesized about OAEs? When?
- who discovered them? when?
- Gold, 1942
- Kemp, 1978
sound pathway
outer ear, TM, ossicles, oval window, fluid filled cochlea, organ of corti
crucial for generating energy needed for OHC movement?
stria vascularis
OAEs are generated by _____ auditory activity
EFFERENT
what do OHCs do?
- their motile properties either enhance or suppress the motion of the basilar membrane
- this action directly affects the amt of stimulation received by the IHCs (what we hear)
3 ways to measure OAEs
- Spontaneous OAES (SPOAEs)
- Distortion Product OAEs (DPOAEs)
- Transient evoked OAEs (TEOAEs)
what’s SPOAEs?
- measurement in outer ear with a sensitive microphone attached to an amplifier and a computer averaging device
- these emissions are estimated to be present in little LESS THAN HALF of all people w/ normal hearing and occur w/o external stimulaiton
SPOAEs more common? used clinically?
- in females
- in right ear
- NOT useful clinically
Explain EOAEs
the probe that’s placed in the ear not only has a microphone to measure the emissions, but it also has a receiver that emits a stimulus to EVOKE an emission from the ear
An OAEs presence is defined by?
at least 6dB above the noise floor
TEOAEs are evoked by?
- stimulates a?
- if present, indicates?
- 2 cautions?
a broadband CLICK stimulus
- stimulates a wide frequency range on the basilar membrane
- NORMAL MIDDLE EAR FUNCTIONING. Hearing is NOT worse than 40 dB at frequence of click
- 1) NOT a hearing test, presence doesn’t mean you don’t have a hearing loss. 2) NOT frequency specific
frequencies of click for TEOAEs?
1k-3k Hz
TOAEs will disappear as soon as?
you have a HL greater than 40 dB. Could still have a mild HL if you have TAOAEs
OAE = what spike on picture?
first spike on left
usually present click for TEOAEs at what dB level?
80
distortion product OAEs are evoked by?
- stimulates a?
- if present, indicates ____?
- disadvantage?
- 2 pure tones presented simultaneously to the ear
- stimulates a SPECIFIC frequency region on the basilar membrane
- HL is not greater than 50 dB. Could still have moderate HL
- takes longer cuz you’re presenting pure tones to each portion of the basilar membrane
Why measure OAEs?
- they’re pre-neural events from the cochlea - helps us distinguish between SENSORY and NEURAL HL in some cases
- can be measured objectively in quote patients in less than 1 min per ear
- non-invasive
- repeatable and reliable
reasons why you might have absent OAEs
cholestiatoma, stenosis, cochlear pathology, external otitis, otosclerosis, cyst
What are people doing with OAEs now? (5)
- newborn screening
- screening individuals who can’t respond behaviorally (e.g., developmentally delayed)
- malingerer
- ototoxic monitoring (industry, chemo, etc.)
- differentiation between cochlear and neural losses
what are electorphysiologic measures? essentially, we?
- measures of electricity generated by the physiologic response of the NS
- place electrodes on the person’s head, stimulate the ear with sound, and measure the electrical activity that is triggered by introducing sound to the ear
earliest electrophys. measure. associated with?
- cochlear microphonic
- hair cell activity
second electrophys. measure? called? happens when? comes from?
- summating potential (from cochlea)
- action potential (end of 8th nerve)
- electocochleography (ECochG)
EcochG
- stimulated with?
- dependent upon?
- can be useful in?
- ratio of what is a critical measure
- is not?
- an abrupt, brief sound like a click
- hearing in 1k-4k Hz range
- dx Meniere’s disease
- SP to AP
- a test of hearing and is VARIABLE
summating potential and AP pic - slide 19
see slide
- SP first, AP higher and second
reasons why SLP student should learn about evoked potentials
- can understand results of ABRs
- can understand what type of test to make a referral for
- research implications
- clinical implications - is therapy working?
what are auditory evoked potentials?
measure of the electrical voltages evoked in the brain in response to acoustic stimulation
how do we measure auditory evoked potentials?
we place electrodes on a patient’s head, stimulate the ear with sound, and measure the electrical activity
3 different Auditory Evoked Potentials, what activity they reflect, and when they occur
- Auditory BS response (ABR) - 8th nerve - 1st 10 millisec
- middle latency - thalamus - 1st 50 millisec
- late latency - auditory cortex - 1st 50 to 250 millisec
study pic of AEP - slide 23
study
what’s ABR stand for? what is it?
auditory brainstem evoked response
- electrodes placed on MASTOID and 2 on forehead
- sound delivered to ears through headphones or oscillator
- measurement is made from 0 - 12 milliseond post stimulus and waveforms are observed that correspond to synaptic junctions along auditory pathway
ABR measures integrity of aud system from ___ to ____
outer ear to BS
ABR testing conditions
infants and kids have to be sleeping
ABR stimuli presented through what type of conduction?
- if using clicks, tests what freq?
- if using tone bursts?
air or bone
- between 2k and 4k
- 500 to 4k
ABR measures?
lower BS and 8th nerve
ABR used to determine?
if there’s an acoustic neuroma, another retrochoclear problem, or to estimate threshold
ABR not a TRUE measure of?
hearing threshold, measures neural synchrony
ABR is most common?
auditory evoked potential
ABR has ___ major peaks that occur at ______
5, intervals (latencies)
Later latency response = ____ amplitude. The shorter the latency, the more ____ proceeds
- greater amplitude
- rapidly maturation proceeds
stimuli used for ABR
clicks
pure tones
define latency
where waves occur in time
what each wave of ABR gives info on*** and timing of each
- distal end of VIII nerve or spiral ganglion, less than 1 ms
- proximal end of VIII nerve and cochlear nuclei, 2 ms
- superior olivary complex, 3ms
- lateral lemniscus, 4 ms
- inferior colliculus, 5 ms
major components of ABR waves
1, 3, 5
missing wave on ABR = ?
that’s where site of lesion is
latency ____ as intensity decreases
increases
timing/distance between 1-3-5 should be?
about 2 milliseconds between each
see pics on slides 36-39 of electrophysiology
look at them
slower than normal latencies (grater than ____ SD from mean) = ?
2
- medical referral for imaging studies to investigate cause
another application of ABR results with children?
can be used for threshold estimation
- reduce intensity of sound and observe how long Wave V is still measurable
Wave 1 small amplitude or delayed or absent?
could indicate cochlear lesion
wave 5 small amplitude or delayed or absent
upper BS lesion
if interpeak latency between 1 & 3 is too long = ?
lower BS lesion
if interpeak latency between 3 & 5 is too long = ?
upper BS lesion
