Last bit for the Final Flashcards
1
Q
sisi test basis
A
extension of the difference limen intensity (DLI) test
- rely on a patient’s ability to detech small changes in signal intensity
- the basis for the test: a person with cochlear lesion can recognize smaller difference limens for intensity than normal hearing individuals
- used to localize pathology to cochlea
2
Q
dual excitation theory
A
abnormal growth of loudness
- occurs with cochlear lesions without damage to inner hair cells
- once the threshold of the inner hair cells of the cochlea is reached: the ear’s ability to detect small changes in intensity is improved= abnormal growth of loudness
3
Q
sisi test procedure
A
detection of brief (200ms) 1 dB increments in a 20dB SL tone
- 20 trials of the 1dB increments presented into the test ear
- at all frequencies or preferably at 2 and 4k Hz
4
Q
sisi instruction and procedure
A
- instruction: ask the pt if they can hear the increments
- training: steady tone at 20dB SL + 5dB increments every 5 seconds (begin with several big increments easily heard by patients
- start the test with 1dB increment
- present at 20dB SL if hearing loss is greater than or equal to 60dB Hl
- present at 75 dB HL (high level sisi test) if the hearing loss is less than 60dB HL
- -to avoid questionable scores (25-65%)
- count # of increments heard and find the %
5
Q
sisi test results
A
- normal, conductive, and retrocochlear:
- negative to low sisi score=0-20%
- SNHL: cochlear site-of-lesion–depends on frequency
- positive/high sisi scores >/= 70% at high frequencies (2-4KHz)
- -1KHz: questionable scores of 40-60%
- -0.25 and 0.5KHz: low scores of 0-20%
- SNHL: retrocochlear site of lesion
- negative to low sisi scores: 0-20%
- **questionable/inconclusiive: sisi score of 25-65%
6
Q
age and sisi tests
A
elderly perform poorer on sisi test
7
Q
what to do if you suspect a cochlear loss
A
- sisi at 2 and 4KHz
- AR decay at 0.5 and 1Hz
- *sisi test and AR decay are complementary
8
Q
patient attention and sisi test (variation of test in improve attention)
A
important to avoid false negatives
- cochlear HL: respond to the majority of increments
- to avoid false positives, randomly reduce to increment to 0dB
- retrocochlear HL: respond to few increments
- -to avoid false negatives, randomly increase the increment to 4 dB
9
Q
sisi test and number of increments variation
A
- use 10 increments
- -if the pt hears 90% or more then you know you have cochlear
- -if the pt hears 10% or less then you have a low score which is neutral
- ten continue to 20 increments if the pt hears greater than 10% and less than 90%
10
Q
sisi procedural variation: increment size
A
1 dB increment is the method of choice, but 0.75db increment is better
11
Q
sisi test specificity and sensitivity
A
- cochlear (specificity) about 85%
* eighth nerve (sensitivity) about 65%
12
Q
bekesy audiometry basics and what is allows for
A
by george von bekesy
automatic audiometry
industrial and military hearing screenings
pt controls the level of the tone
allows for: threshold assessment and site of lesion testing because of auditory adaptation
13
Q
bekesy to measure auditory adaptation
A
there are two modes of pure tone presentation, interrupted (I) and continuous (c)
- there are also two tracing modes, sweep frequency trackings from low to high or reverse and fixed frequency plotting at each frequency
- ***adaptation should only occur for c not i
14
Q
how to read a bekesy printout
A
a sawtooth graph
- downward sweep= period of inaudibility
- upward sweep= period of audibility
- midpoint= correlated well with behavioral threshold
- —threshold is calculated as the midpoint of the tracing between audible and inaudible
15
Q
range of frequencies measured in bekesy
A
100-10000Hz
16
Q
bekesy type I tracing
A
sweep frequencies are characterized by an overlapping of I and C tracings with a tracing width of about 10dB
*found with normal, CHL, and SNHL of unknown etiology
17
Q
bekesy type II tracing
A
the C tracing falls below the I, generally at or above 1000Hz (not more than 20dB)
*usually seen in SNHL with cochlear origin. It is strictly a cochlear pattern
18
Q
bekesy type III tracing
A
dramatic drop of the C below the I with a separation of 40-50dB or higher
* Consistent with retrocochlear pathology
19
Q
bekesy type IV tracing
A
C dropping below the I at frequencies lower than 1000Hz as opposed to the type II
*could be cochlear or retrocochlear
20
Q
bekesy type V
A
I is poorer than C tracing
- for at least 2 octaves
- minimum of 10dB separation (76% of cases?)
- is nonorganic (malingering) because subject has own standard for loudness for the continuous tone (40% of cases)
21
Q
what are the two bekesy modifications to improve the accuracy of diagnostic results?
A
- reverse (Forward-backward) bekesy tracing
* bekesy comfortable loudness technique
22
Q
reverse bekesy modification procedure
A
separates cochlear from retrocochlear disorders
- step 1) conventional bekesy (forward: low to high frequency)
- 1st is c tracing, then I tracing
- step 2) do the C tracing again, but this time in reverse (high to low frequency)
23
Q
interpreting reverse bekesy tracings
A
compare the two tracings
- if there is an overlap/little difference between the 2= normal
- if there is greater separation and the reverse C tracing is poorer than the forward c tracing at mid to high frequencies shows retrocochlear (VIII tumor for example)
24
Q
bekesy comfortable loudness modification
A
same conventional bekesy tracing except search for the comfortable loudness
- press the button when the signal is just uncomfortable loud and release it when the signal is just less than comfortable loud
- **do this with masking noise in the nontest ear
25
bekesy comfortable loudness rationale
retrocochlear disorders initially appear at suprathreshold level
*recording above the threshold would therefore be more sensitive to retrocochlear disorders
26
bekesy comfortable loudness patterns
```
there are three patterns
Negaative patterns:
*N1: overlapped
*N2: c tracing is above I
*N3: c tracing is below I
**no retrocochlear lesion for N1-N3 (normal hearing or cochlear HL)
```
positive patterns:
* P1: C tracing falls far below I at high frequency
* P2: C falls far below I at low and or middle frequencies
* P3: forward-backward discrepancy
- c is normal in forward but abnormal in backward
* *these are all retrocochlear and the adaptation often happens to the c tone
27
Bekesy comfortable loudness limitations
not all ears could be classified as negative or positive
| *19% of retrocochlear cases and 8% or the other ears did not fit into the six categories
28
brief tone audiometry via bekesy audiometry
(temporal integration intensity-duration relationship)
*measuring/comparing thresholds for (I) tones at 2 durations:
1= very short durations (20 msec)
2= longer durations (200msec)
****determine how much of a threshold change is needed to offset duration difference from 20 to 200 msec
29
interpreting brief tone audiometry via bekesy
* normal hearing: need an intensity change of 10dB to compensate for the effect of a 10-times change in duration (20 to 200 msec)
* cochlear cases: need a smaller than normal intensity change to offset a 10-times change in duration; temporal integration function is shallower than normal
30
limitation of brief tone audiometry via bekesy audiometry
not sensitive to retrocochlear lesions
| *there is too much overlap between the results for cochlear and retrocochlear disorders
31
site of lesion testing : binaural interaction (BI)
| there are two tests, name them!
* sensitive to brainstem lesions
* tests are:
- binaural fusion (BF)
- masking level difference (MLD)
32
binaural fusion test procedure
the pt's task is to integrate the two parts of the target stimulus=binaural fusion
* require info from both ears
* sensitive to brainstem lesions
* uses 2 channel audiometer to present low pass segment of a word to one ear and the high pass segment of the same word to the other ear
* the test is scored by calculating the % correct
- poor performance= brainstem disorders
33
binaural integration masking level difference (MLD)
CAP test battery
* a test of lower brainstem integrity and release from masking
* interactions at the level of the SOC
* present 2 stimuli binaurally (or monaurally)
- signal (S) is 500Hz tone or speech
- Noise (N)
* compare noise/ masking levels in the 2 conditions measure while the noise or signal is:
- -homophasic (in phase) and
- -antiphasic (out of phase)
* calculate the dB difference of the masking levels between these 2 conditions (in and out of phase)
34
MLD results
release from masking phenomenon: the tones become audible when S and N are out of phase (SpiNo or SoNpi)
* then the noise must be raised further to mask the tone again (end test at this dB level)
* **MLD is the difference between the noise level needed to mask the tone/speech for the out of phase condition and the in phase condition (SoNo)
- ---the amount of dB that the noise must be raised to mask the tone again in the out of phase condition
35
MLD normal results
a release from masking
* normal MLD values (frequencies less than or equal to 500Hz:
- -SoNo/SpiNo=15dB
- -SoNo/SoNpi=13dB
* lesions or the rostral brianstem, subcortec and cortex dont affect MLD
36
MLD explanation
in-phase condition, both S and N (competing stimuli) originates from the same percetpual sources-hard to be perceptually separated
*out of phase condition S and N originate from different perceptual sources--listener is better able to perceptually separate the competing stimuli
37
MLD sensitivity
hit rate was 69% for 27 pts with different brainstem lesions
38
MLD maturation factor
the age at which the magnitude of the MLD reaches adult levels depends partly upon masker bandwidth
- -for wider BWs, children perform like adults by 5-6 years or age
- -for narrower BWs, adult-like performance is not reached until an older age
39
MLD abnormal results
any compromise in the brainstem would result in less release from masking (reduced MLD)
* limitations (confounding factors):
- -reduced MLD with:
- ---history of OM
- ---learning disability
- ---peripheral HL (degree of HL affects the MLD and may contaminate your results)
40
word recognition testing- PI/PB function
| basic definition
performance intensity (PI) function when phonectically balanced (PB) word lists are used
41
PBmax
the maximum score on the PI/PB function
42
plateau for PI/PB
PI function evens out when the intensity of presentation is raised above the PBmax level
* the score does not improve or decline if intensity is raised
* **shows normal PI/PB function
43
rollover for PI/PB
when a reduction of speech recognition scores occurs above where PBmax is obtained
* *rollover of PB function indicated abnormal
- --cochlear is rollover
- --retrocochlear is severe rollover (>0.41)
44
site of lesion tests protocol
1) conventional audiometry including SRT, WRS, tymps, ART
a) if all is normal, no further testing needed
b) if large discrepancy b/t ears, go on to further testing
c) if ART are absent or elevated above expected amount, go on to further testing
45
can the specific pathology of a retrocochlear pathology be identified?
no not even through the most advanced audiologic procedures
*the most effective way to approach the differential diagnosis of cochlear vs. retrocochlear pathologies is through a combination of behavioral, electrophysiologic, and radiographic methods
46
list of qualitative tests for pseudohypacusis (4)
1) audiogram/shadow curve
2) stenger/ modified stenger
3) acoustic immittance measurements
4) low level PI/PB
47
quantitative tests of pseudohypacusis
1) auditory evoked potentials
2) automatic audiometry and lombard test
3) swinging story test, low level PB word test
4) ascending/ descending methods
5) pulse count methods, yes/no test
48
other terms for pseudohypacusis
* nonorganic HL
* functional HL
* malingering
* false or exaggerated HL
49
reasons for pts to be uncooperative during HE
* dont understand the test
* incapable of appropriate responses
* poorly motivated
* inaccurate response due to unconscious motivation
* try to conceal a handicap
* exaggerating or feigning a HL
50
organic hearing loss
real hearing loss
* results from anatomical or physiological abnormalities
* pt response are reliable and consistent
* the hearing threshold represents the actual hearing threshold
51
nonorganic hearing loss
functional hearing loss
* a hearing loss unrelated to pysical or organic impairment in the auditory system
* exagerated HL could be here too
* pt gives voluntary false negative response (pt gives the false impression he has HL while actually is normal)
52
exaggerated HL
nonorganic HL superimposed on an organic HL
53
consciously simulated=malingering hearing loss
* the pt is faking a hearing loss that doesnt exist
- or-
* the pt is exaggerating his actual hearing loss
54
conversion neurosis
unconscious unorganic hl
* hysterical pts may manifest psychologial problems (aphonia, paralysis, hearing loss, etc.)
* pt actually experiences impaired hearing and truly believes the hearing loss is real
55
facticious disorders
pt knows they are intentionally producing a false malady but are quite unaware of why
56
why fake HL instead or other problems
* they were focusing their attention on hearing
* *a relative or friend has a hearing problem
* **ear infection, physical trauma, noise exposure, tinnitus
57
percent of pts with bilateral pseudohypacusis vs unilateral
bilateral: 72%
unilateral: 28%
58
why bilateral pseudohypacusis?
* the underlying organic loss is most likely bilateral
* easier to exaggerate the response for both ears
* the subject assumes that real (organic) loss should be bilateral
59
why unilateral pseudohypacusis?
* sensing a difference b/t ears might influence the pt to exaggerate the impairment in only one ear
* exaggerate the impairment in the poorer ear to get more compensations due to the loss in that ear
* feign a loss in the good (better) ear if the pt believes losses should be bilateral, or to maximize the benefits from a hearing loss in both ears instead of just one
60
why do adults feign o exaggerate a true hearing loss?
1) financial benefits
* injury-related lawsuits
* veterans who lost their hearing while in service
* medicolegal pts with NIHL
- -24% of the 116 workers were pseudohypacusis in a study?
2) social and occupational benefit
* get special attention, preferential treatment and support
3) psychosocial factors--goals
* feel a sense of gain by appreaing to have a hearing loss
* explain to society that they are blameless for inadequate social behavior
61
pseudohypacusis in children, why?
* not the financial benefit
* justification (excuse for poor academic achievement
* school/family issues, attention, and emotional support
* **nonorganic hearing loss should be diagnosed as soon as possible before referrals for otologists are made
62
degree of organic loss affects the size of functional loss in 2 ways:
1) the target level: the loudness level that is used
2) amount of recruitment
(it is an inverse relationship; the configuration of the functional loss is related to the configuration of the underlying hearing loss; there is a loudness difference due to recruitment)
(also recruitment at higher frequencies with severe loss, causes loudness to reach the target at lower SLs, this results in a flattened audiogram)
63
what to do when someone shows a hearing loss you dont think is true?
* separate out the nonorganic component from organic hearing loss
* determine the extent of the organic component not the motivation for the nonorganic hearing loss
* address underlying cause of the organic hearing loss with referral when appropriate
64
when to expect pseudohypacusis before testing
should always be in your mind so you dont miss when its presence is indicated
* referral for hearing tests following an accident, veterans
* case history is very important; observe responses to questions and the manner these responses are offered
65
symptoms of pseudohypacusis in case history
* over-reliance on lip reading
* cupped hand over the ear
* ask for inappropriate repetitions of words
* constantly readjusst a hearing aid
* exaggerated statements and vague descriptions of hearing difficulty
66
indications of pseudohypacusis in test situations
* inconsistent test retest reliability
* extremely slow responses
* very few false positive in silent period
* lack of agreement between SRT and PTA (SRT is lower because loudness of speech is associated with low frequency componenets which grows more rapidly than tones in the speech frequencies
* misses spondee words previously repeated correctly at lower levels
* repeat only one syllable and not the other of spondees
* lack of shadow curve with unilateral loss
67
purpose of pseudohypacusis tests
* identify the presence of functional hearing loss
| * to estimate the patient's actual hearing loss
68
when is stenger used?
the most popular pseudohypacusis test
* unilateral pseudohypacusis
* unilateral hearing loss (organic)
* asymmetrical hearing losses
- -at least 20dB between the ears (preferrably greater than 40dB) at each frequency
69
requirements of stenger test
two channel audiometer with
* a separate HL dial for RE and LE
* independent control over intensity levels for RE and LE
* *no special instructions should be given to pt
- ---tel them every time you hear a tone, please raise your hand
70
binaural fusion
a tone presented to both ears is heard as a single, fused image that seemed to be located somewhere in the head
*the image is heard in the midline of the head if the tone has the same SL in both ears=midline lateralization
71
stenger effect
when two tones of the same frequency are presented simultaneously into both ears, only the louder tone will be perceived
72
stenger procedure
present 10dB above threshold in the better ear and 10dB below threshold in the poor ear
* true loss: hears only the tone in the better ear--negative stenger
* nonorganic loss: dont admit hearing the tone in the poor ear, dont respond to the tone in the better ear--positive stenger
73
negative stenger test
* pt is unaware of the tone in the poor ear
* pt responds to the tone in the better ear
* tone is perceived louder in better ear
* the poor ear threshold is probably correct
74
positive stenger
* pt doesnt admit t hearing the tone in the poor ear
* is unaware of the tone in the better ear which they definitely should hear because it is 10dB SL due to the stenger effect
75
advantage of stenger test
good rapid screening test
* detect presence or absence of unilateral or asymmetical functional loss
- -25 out of 31 cases of nonorganic loss
* more sennsitive when better ear is normal
76
disadvantage of stenger test
screening test
* doesnt determine the degree of organic hearing loss
* *perform MCIL test: a modification of stenger test
77
MCIL test procedure
minimum contralateral interference levels (MCIL)
preset 2 tones simultaneously: 10dB SL in the better ear and 0dB HL in poor ear, increase poor ear by 5dB HL until the pt fails to respond
**pt will stop to respond due to the stenger effect (positive stenger), they are unwilling to admit to hearing the tone in the bad ear
78
what does the MCIL tell you?
the lowest hearing level in the poor ear that produces the stenger effect is within 20-14dB from the true threshold
79
modification of the stenger test: speech stenger test
*same principle as for pure-tone stenger
-using spondee rather than pure tone
*same requirement
-2 channel audiometer with VU meter
-monitored live voice or recorded material
*same criteria for use
-unilateral cases (more sensitive)
SRTs of the RE and LE> 20dB difference
*instruction to pt: repead every word you hear
80
interpretation for speech MCIL
* admitted interference
- organic HL--true threshold
- admits to hearing speech in poor ear and raises hand, a kind of interference
* interference level=positive stenger
* not responding to speech in better ear, when the signal was presented simultaneously at higher level to poor ear
81
advantage of speech stenger test (i think she means MCIL)
provides quantitative information
82
low-level phonetically balanced (PB) word tests procedure for pseudohypacusis
high level is 40dB SL and low level is 20-10dB SL
| *procedure: present PB words at 20dB SL
83
low level PB tests results for pseudohypacusis
*normal hearing: 75-80% at 20dB HL suggest normal hearing for speech, higher scores are not expected until 30-40dB SL
*pseudohypacusis:
high PB WRS approaching PB max, at levels only slightly above their admitted thresholds
84
acoustic reflex thresholds for pseudoypacusis
it is a physiological test used to identify functional pts--since the 1960s
* normal: ARTs should be 70-80dB above pure tone thresholds or ART is 85-100dB HL for pure-tones
* pseudohypacusis: ART is considered unusually low if it is at or below the admitted threshold for the same frequencies, 5dB above the admitted threshold that is > or = 90dB HL, below the 10th percentile of the ART distribution for normal and cochlear hearing loss subjects
85
ART limitations for pseudohypacusis
* presence of conductive hearing loss
* ARTs are unaffected by the degree of loss up to 50-60dB HL
* ARTs at or above the 10th % doesnt rule out an exaggerated loss
86
SPAR testing
sensitivity prediction from acoustic reflexes
* noise-tone difference
- -normal hearing: about 20dB difference
- -50dB loss or lower: less than 20dB difference
- -above 50dB loss: about 20dB difference
87
limitations of SPAR testing
gross estimates with a lot of variability
- used to identify the presence of significatn HL, NOT to predict the degree of HL
* ART for BBN is affected by
- -SNHL- a significant degree of organic SNHL
- -aging- noise--ART increases with advancing age (pts 45 yrs old or more)
88
pseudohypacusis with automatic audiometry: conventional type V bekesy
I tracing is poorer than C
*separation of I and C for 2+ ocatves
*10dB minimum separation
(i tone makes it hard for pt to keep constent measure of their predetermined loudness level for tones)
"c and i tones hace unequal loudness"
***2% false positives in this test with CHL and 3% with SNHL
89
bekesy modification (LOT) purpose and procedure
lengthened time off- bekesy test designed from jergers type V sweep-frequency bekesy pattern
* purpose: produce less false negatives when identifying functional hearing loss
* procedure: monaural 1-2 minute fixed bekesy tracings mostly at 1000Hz
- 1)conventional bekesy (200msec on and 200msec off) C then I tracing
- 2) I tracing in one ear in the LOT mode (200msec on, 800msec off) and test same frequency as conventional
90
LOT bekesy results
* it increases the degree to which the I tracing falls below the C tracing (makes it fall farther)
* positive LOT suggests a functional component
91
pseudohypacusis bekesy modification DELOT
| procedure
descending lenghtened off time
* employs an ascending measurement procedure and compares ascending and descending bekesy tracings
* procedure: conveentional bekesy ten LOT testing, then DELOT?
- DELOT presented 25dB above the highest LOT threshold, pt is asked to hold down a button until the sound is no longer heard
* **basically you do lot which is ascending intensity runs, then do delot which is descending intensity runs
92
DELOT test results
* DELOT tracing is far below LOT tracing (higher threshold levels)
- bigger gap between C and I tracings
- better identification of type V bekesy
* a positive DELOT suggests a functional component
* DELOT is highly sensitive and specific for functional HL
- low error rates make this test a valuable addition to routine audiometric batteries
* recommended approach: screening for functional loss at 500Hz with DELOT
- put this test 1st in the sequence to determine the fakers before doing a whole battery of tests
93
pseudohypacusis bekesy modification BADGE
bekesy ascending descending gap evaluation; this test distracts the pt's attention to maintain the same reference level for the exaggerated threshold when it is approached from below and above (ascending and descending)
94
BADGE test procedure
testing threshold for te same tone separately with ascending and descending approach
1) continuous ascending (CA) approach: start at 0 dB and tone is automatically increased until pt hears it (about 1 minute)
2) pulsed ascending (PA) approach: start at 0 dB and threshold is tracked or 1 min
3) pulsed descending (PD) approach: start 30-40dB above PA threshold, threshold is traced for 1 minute
95
BADGE results
* normal: consistent response with 5 dB variance
* organic loss: less variability: ascending and descending gap is narrow
* nonorganic loss: inconsistent responses, ascending an descending gap is wide
96
bekesy audiometry modifications
LOT, DELOT, and BADGE tests are more sensitive than type V bekesy
* disadvenatge: qualitative test
- -they dont indicate the magnitude of the true threshold
97
pseudohypacusis test sequence
1) SRT (then stenger if indicated)
2) AC thresholds (the stenger if indicated)
3) word rec (start at low SLs if you suspect functional loss)
4) BC thresholds
5) other tests
- a) bekesy
- b) immittance measures
- c) stenger for unilateral or asymmetrical loss
98
pure tone DAF test
delayed auditory feedback for pseudohypacusis
* called the "tone tap test"
* ask the subject to tap a pattern over and over, the tones are delivered back to the ear with a 200msec delay and the level increases until the pattern changes (there is also a button connected to a chart recorder to record any change in pattern)
* with pseudohypacusis, there will be a disruption of the pattern and recorded pattern at levels lower than the pts admitted PTA meaning the pt heard the DAF tones, estimate threshold within 5-10dB of the true threshold
* limitation: pt should be able to produce the tapping pattern and maintain it
99
DAF speech test
for pseudohypacusis
* principle: auditory feedback; people hear what they are saying simultaneously as they are talking, making them stutter
* procedure: ask pt to read a passage (they speak into mic and hear themself through headphones)
- output of mic gets delayed 100-200msec and is then directed into earphones at lower level than admitted SRT threshold
* AUD seeks the level where delay causes difficulty in speaking (rate, fluency, intensity, and vocal quality)
* Results: organic HL= no effect on speech because they dont hear it (below SRT)
- pseudohypacusis= disruption of the talkers speech production
100
Lombard test
pseudohypacusis test; principle is lombard reflex
* elevation of vocal effort that occurs when talking in the presence of noise
- normal hearing subjects: when they hear surrounding noise they raise their voice to compensate
* test procedure: ask pt to read paragraph aloud, gradually increase making level AU, record masking level at which pt raises voice while reading
* normal hearing: pt raises reading volume with increasing masking and lowers with decreasing suggesting pt hears the masking noise
* pseudohypacusis: pt raises level of speech at a noise level lower than volunteered threshold
101
lombard test disadvantages
* it is a screening test
* not greatly sensitive or specific
* can't determine the magnitude of the error by this test
102
lombard test modification: quantitative measure
* same procedure as lombard except: pt is asked to read into mic input of a live voice speech audiometer, the talkback and attenuator dial is left at one position without change, AUD monitors the level of the patient's speech on the VU meter (increase peak value from 0 VU to 2 VU)
* advantage: estimate the magnitude if the functional loss (quantitative levels)
* disadvantages: no normative date; wide variety
- -a person is used to listen in noisy situations, he can control his own voice in spite of the noisy background
103
evoked otoacoustic emissions (OAEs)
* are sound emitted from the OHCs of a healthy cochlea
* a test of cochlear function and site of lesion testing
* Types: transient OAEs or distortion OAEs
* a good screening test for functional loss
* identify exaggerated losses in patients, whose real hearing threshold is = 30dB HL
104
TEOAE or CEOAE
transient evoked or click evokes oae
*are response to clicks
*present oae response: normal cochlea/OHCs, normal middle ear
(rule of thumb, if hearing is better tan 35dB, OAEs are present)
105
DPOAE
distortion product OAE
| *should be 6-10dB above the noise floor
106
OAE limitations
* affected by degree of SNHL
- -of no value in cases with some organic hearing loss of >40dB
* affected by middle ear pathology
- -very sensitive to conductive hearing loss
107
evoked potential audiometry
| different measures/types
* objective tests
* do not require any physical response from the pt
* early
- -electrocochleagraphy (EcochoG)=5msec
- -auditory brainstem response (ABR)=10-12ms
- -80Hz auditory steady state response (80Hz ASSR)
* middle
- -middle latency response (AMLR: middle)=50-80ms
- -40Hz ASSR
* late
- -late latency response (LLR: late/long)= 100-140ms
108
auditory brainstem response (ABR)
tests the neural integrity of auditory pathways up to brainstem level
* site of lesion testing
* far field electrodes used
- -placed on the scalp, mastoid, or earlobe
- -responses are very small and need to be extracted from background noise
109
ABR peaks
* wave 1=VIII nerve distal part
* wave 2= VIII nerve proximal part
* wave 3= cranial nerve and SOC
* wave 4= soc and LL
* wave 5= LL and IC
110
ABR advantages and disadvantages
advantages:
indentify pts with pseudohypacusis, estimate hearing sensitivity in all cases (should be used with all uncooperative pts)
disadvantages:
use of click is less freq specific
most sensitive to high freq (2-4KHz)
ABR thresholds is within 30dB re audiometic thresholds
should be interpreted with caution
111
ABR pathologic variables (disadvantages)
Conductive HL: prolongation of all waveforms
SNHL: depends on degree and frequency of stimulus (low freq loss will have little effect on ABR)
**to improve freq specificity: use linger duration signal like a tone burst
----narrow band stimuli
---to get freq specific threshold data
(or just use another AEP)
112
Corital Auditory Evoked Potentials (CAEP) or SVP
slow vertex potential (SVP)
- -long latency AEP
- -N1-P2 response
- -frequency specific
*SVP threshold is 5-15 dB above PTA
113
what not to do with pseudohyapcusis
* be judgmental, accusatory or confrontational
* use words like malingering, feigning
* use words such as functional, nonorganic, psychogenic
114
what to do with pseudohypacusis
```
emotional support
reinstruct pt and emphasize importance
relate inconsistent responses to miscommunication
if the response is still inconsistent:
-cant make diagnosis b/c discrepancies
-schedule another appointment
```
115
pseudohypacusis test sequence
1) SRT and stenger if indicated
2) AC thresholds and stenger if indicated
3) word rec--start at low SL
4) BC thresholds
5) other tests
- a) bekesy
- b) immittance measures
6) other AEP tests (OAE, ABR, ASSR, N1-P2)
7) electrodermal testing
116
swinging story test for pseudohypacusis
* need 2 channel audiometer (story switches from one ear to both and to the other)
* procedure: listen to the story and repeat it after
- -present slightly above the threshold in the better ear and 10dB lower in the poor ear
* if pt hears the whole story=functional loss
* if pt only hears what was in the good ear= HL is real
* used to detect a unilateral loss
* if the hearing level in the poor is is 30-35dB + worse than the better ear then cross hearing can occur
117
swinging story test modification; varying intensity story test (VIST)
* two parts of a story are combined
- -part I-presented above threshold, 10 dB above SRT
- -part II- presented 30-50 dB below SRT threshold
* 10 questions are given to the pt
- -5 questions for part I
- -5 questions for part II
* organic hearing loss: pts will only answer the questions that were given above threshold
* pseudohypacusis: pt will answer questions that were given above and below thresholds-hearing is better in his poor ear compared to his admitted threshold
* advantage: more standardized test compared to the traditional way of repeating the story
- approximated the auditory threshold for SRT
- can be conducted monaurally or binaurally
118
Ascending-Descending methods (A-D)
pure-tone thresholds are measured using ascending and descending methods--simple and quick
* procedure: ascending approach then descending approach
* normal hearing: pt thresholds within 5-10dB per frequency
* pseudohypacusis: >10dB difference with pseudohypacusis
- a difference as large as 30dB
* **thresholds are better with ascending than descending
* **can use maual pulsed tones with standard time off (SOT)
119
pulse count methods of pseudohypacusis
present a number of pure tone pulses rapidly
| *very intensity above and below threshold and ask them to count the number of pulses heard
120
yes-no method
used with kids (they hear the tone if they say no)
