Term
Rationale for Tone-Burst ABR:
-Click-evoked ABR is good place to start, but not sufficient to identify audiometric configuration – to program ___ ___
-At a minimum, estimate HF hearing sensitivity (___ Hz) & LF hearing sensitivity (___ Hz) for each ear
-If possible, add testing at ___ Hz to determine audiometric configuration |
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Definition
| hearing aids; 4000; 500; 1000 |
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Term
Tone-burst ABR-Stimulus Parameters:
-Use ___ earphones
-Alternating ___ to reduce likelihood of a frequency following response
-___: how the rise/fall parts of the tone burst are shaped; some methods decrease “spectral splatter” & improve frequency-specificity; ___ ___ is best
-Duration: r/f & plateau times vary depending on the ___; use longer times for ___ freqs to include more cycles to increase chance that stimuli sound like tones |
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Definition
| insert; polarity; Ramping; Blackman window; frequency; lower |
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Term
Frequency Following Response:
-___ latency AEP of the same frequency as the low-frequency tone burst stimulus |
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Definition
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Term
Tonebursts – Stimulus Duration:
-duration in the same # of cycles instead of equal ms means the energy is ___ for each freq.
-# of cycles per ms increases from ___ to ___ frequency
-Example: in a time period of 2 ms, there is:
• __ cycle for a 500 Hz tone burst
• __ cycles for a 4000 Hz tone-burst |
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Definition
| equivalent; low; high; 1; 4 |
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Term
Intensity-dB nHL (normal hearing level):
-Intensity levels on screen may be in dB ___
-For tone bursts, outputs may go up as high as ___
-dB nHL Example: If max setting for 500 Hz tone-burst is 110, but normal-hearing persons have average threshold of 30 dB, then dial setting of 110 =___ dB nHL |
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Definition
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Term
| What do you need to do on your ABR equipment before you test patients? |
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Definition
| Obtain behavioral on ABR equipment |
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Term
Toneburst ABR – Time Window:
-Extend analysis time to ___ ms for LF tone bursts |
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Definition
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Term
Toneburst ABR – Filter Settings:
- When testing infants & children: set high pass filter cutoff to __ or __ Hz
-ABR spectrum from babies has a lot of ___ frequency energy whether it is elicited via clicks or tone-bursts
-Turn ___ Hz notch filter off |
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Definition
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Term
Estimate Pure-tone Behavioral Thresholds from ABR:
-Predictable relationship between _______ ABR and ___ thresholds
-Find lowest intensity level that produces a reliable wave __
-Lowest intensity level that yielded reliable wave V ___ be
equal to the behavioral threshold
-To generate ABR, it takes _____ higher intensity compared to
behavioral threshold |
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Definition
| tone-burst; behavioral; V; will not; 5-10 |
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Term
Correction Factors-Tone-burst ABR:
-ABR intensity level (in dB nHL) minus CF =estimated ___ ___
-500 Hz: __-__ dB
-1000 Hz: __-__ dB
-2000 Hz: __-__ dB
-4000 Hz: __-__ dB |
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Definition
| audiometric threshold; 15-20; 10-15; 10-15; 10-15 |
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Term
| Describe where to mark Wave V to obtain the correct absolute latency value |
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Definition
| Mark wave V latency from the last data point before the waveform drops off (not the middle of the peak) |
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Term
| Use absolute latencies, calculate the I-III, III-V, & I-V ___ ___ |
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Definition
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Term
Waveform Morphology – TB ABR:
-For lower frequency TB at ___ intensity levels the morphology of waveforms changes
-Wave __ is less likely present
-To estimate thresholds, look for reliable wave __
-Wave V latency increases as TB frequency ___
-For lower freqs, at lower intensity levels, peak will appear ___
-Do not have to mark precise peak, look for lowest intensity level at which wave V ___ |
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Definition
| lower; I; V; decreases; rounded; repeats |
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Term
What does this latency-intensity function depict?
[image] |
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Definition
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Term
What does this latency-intensity function depict?
[image] |
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Definition
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Term
What does this latency-intensity function depict?
[image] |
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Definition
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Term
-Conduct a click-evoked ABR at a ___ intensity level
-Presentation level: __-__ dB HL
-Threshold search: you would ___ intensity level |
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Definition
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Term
If click-evoked ABR shows normal latencies, then...
-Record _______ ABR and/or ___ to confirm normal auditory sensitivity
-Start a ___-specific ABR test with ___ Hz tone bursts |
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Definition
| tone burst; OAEs; frequency; 500 |
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Term
If click-evoked ABR shows delayed Wave I latency at a high intensity, then...
-Consider ___ loss
-Prepare to do a _____ ABR
-If have not already done so, measure ____
-Refer to ___ |
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Definition
| conductive; BC; tympanometry; ORL |
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Term
If click-evoked ABR is normal at high intensity, but abnormal or absent at low intensity...
-Suspect mild or moderate __HL
-Estimate thresholds with ___ ___
-Verify sensory auditory dysfunction with ___ |
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Definition
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Term
If click-evoked ABR is abnormal or absent at high intensity...
-Suspect ___ SNHL
-Record ABR at ___ intensity level
-Consider conducting an _____________ test |
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Definition
| severe; maximum; auditory steady state response (ASSR) |
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Term
If there is no clear click-evoked ABR at high intensity...
-Suspect ___/___
-Record ABR with ___ and ___ stimulus polarity
-Look for cochlear ___
-Record OAEs to verify integrity of ____ |
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Definition
| AN/AD; rarefaction; condensation; microphonic; OHCs |
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Term
Bone-Conducted ABR:
-Purpose: To estimate __-__ gap, can be recorded in patients of all ages
-Advantage: a present wave I suggests ___ cranial nerve activity on the side of the stimulus which allows ___-specific information to be collected
-When? For anyone at risk for _________ |
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Definition
| air-bone; 8th; ear; middle ear disorder |
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Term
BC ABR-Special Considerations:
-Max output of BC oscillator is __-__ dB nHL
-BC oscillator rolls off ___ ___ energy compared to AC transducers; but enough energy at __-__ kHz to activate ABR
-May have to ___ BC oscillator by hand
-Separate the BC oscillator from the ___ electrode as much as possible |
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Definition
| 45-50; HF; 2-3; hold; inverting |
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Term
BC ABR-Acquisition Parameters:
-___ ____ instead of insert earphones
-Have to place ___ electrode on earlobe; exclude ___ placement
-Alternating ___ to reduce noise in ongoing EEG
-Slow down click rate to ___ or ___ c/s to enhance Wave I amplitude
-Set high pass filter relatively ___ (30, 75, or 100 Hz) since ABR has mostly LF energy
-Complete more ___ |
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Definition
| BC oscillator; inverting; mastoid; polarity 11.1; 21.1; low; sweeps |
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Term
BC ABR - Analysis:
-ABR Wave I present in ear ___ to BC stimulus confirms response from the test ear cochlea & minimizes need for ___ in NTE |
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Definition
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Term
| Infant ABR does not reach adult-like values until __-__ months of age |
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Definition
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Term
| How does a neural disorder effect the ABR? |
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Definition
Abnormal-pattern depends on location and extent of lesion. CPA tumor-normal wave I latency & amplitude & either a delay
of inter-wave latencies or absent wave II &/or wave V |
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Term
What does this suggest?
[image] |
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Definition
| Right retro-cochlear pathology |
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Term
What does this suggest?
[image] |
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Definition
Right 8th nerve tumor
-I-V interpeak interval should be about 4 ms
-I-V IPL > 4.5 ms is abnormal
-Wave V inter-aural latency is greater than 0.4 ms |
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