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ABR 2
Physiologic Measures 1
30
Audiology
04/19/2017

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
Definition
 hearing aids; 4000; 500; 1000
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
Definition
 insert; polarity; Ramping; Blackman window; frequency; lower
Term
 Frequency Following Response:-___ latency AEP of the same frequency as the low-frequency tone burst stimulus
Definition
 Short
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
Definition
 equivalent; low; high; 1; 4
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
Definition
 SPL; 115; 80
Term
 What do you need to do on your ABR equipment before you test patients?
Definition
 Obtain behavioral on ABR equipment
Term
 Toneburst ABR – Time Window:-Extend analysis time to ___ ms for LF tone bursts
Definition
 20
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
Definition
 30 or 75; LF; 60
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 ___ beequal to the behavioral threshold-To generate ABR, it takes _____ higher intensity compared tobehavioral threshold
Definition
 tone-burst; behavioral; V; will not; 5-10
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
Definition
 audiometric threshold; 15-20; 10-15; 10-15; 10-15
Term
 Describe where to mark Wave V to obtain the correct absolute latency value
Definition
 Mark wave V latency from the last data point before the waveform drops off (not the middle of the peak)
Term
 Use absolute latencies, calculate the I-III, III-V, & I-V ___ ___
Definition
 inter-wave intervals
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 ___
Definition
 lower; I; V; decreases; rounded; repeats
Term
 What does this latency-intensity function depict?[image]
Definition
 CHL
Term
 What does this latency-intensity function depict?[image]
Definition
 SNHL
Term
 What does this latency-intensity function depict?[image]
Definition
 Retro-cochlear
Term
 -Conduct a click-evoked ABR at a ___ intensity level-Presentation level: __-__ dB HL-Threshold search: you would ___ intensity level
Definition
 high; 70-90; decrease
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
Definition
 tone burst; OAEs; frequency; 500
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 ___
Definition
 conductive; BC; tympanometry; ORL
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 ___
Definition
 SN; tone bursts; OAEs
Term
 If click-evoked ABR is abnormal or absent at high intensity...-Suspect ___ SNHL-Record ABR at ___ intensity level-Consider conducting an _____________ test
Definition
 severe; maximum; auditory steady state response (ASSR)
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 ____
Definition
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 _________
Definition
 air-bone; 8th; ear; middle ear disorder
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
Definition
 45-50; HF; 2-3; hold; inverting
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 ___
Definition
 BC oscillator; inverting; mastoid; polarity 11.1; 21.1; low; sweeps
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
Definition
Term
 Infant ABR does not reach adult-like values until __-__ months of age
Definition
 18-24
Term
 How does a neural disorder effect the ABR?
Definition
 Abnormal-pattern depends on location and extent of lesion. CPA tumor-normal wave I latency & amplitude & either a delayof inter-wave latencies or absent wave II &/or wave V
Term
 What does this suggest?[image]
Definition
 Right retro-cochlear pathology
Term
 What does this suggest?[image]
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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