ABR Exam 1 Questions With Complete Solutions
A-D limits Correct Answers input signals cannot exceed the
voltage limits of the A-D converter
ABR Characteristics of CHL Correct Answers Absolute
latency of all components is prolonged in parallel fashion, so
IPLs are within normal limits
Absolute Latency Correct Answers time from the onset of the
stimulus to the peak of the response component
AC vs BC ABRs Correct Answers about 0.5 msec longer
latency for BC
infants more ABRs are seen with BC than AC at 30 dB nHL
BC latency does not change above 55 dB nHL
Amplitude Correct Answers (absolute) measure peak to trough
but we say peak to peak- we measure this way to reduce
variability due to baseline
Analog filtering Correct Answers changing the lower cut-ff and
upper cut-off frequencies
Analog section consists of what? Correct Answers Preamplifier
Differential amplifier
filtering of the signal
Gain added to the signal
At what time does digitizing begin? Correct Answers 0
,benefit of digital filtering Correct Answers doesnt create
distortions in amplitude or latency like analog filtering does
best stimulus to use for hearing status as a function of frequency
Correct Answers frequency specific tone burst
best stimulus when looking for site of lesion Correct Answers
clicks
Bone conduction ABR Correct Answers narrowband compared
to AC transducer
overall output is reduced
output decreasing with increasing frequency
threshold is elevated
limits dynamic range to 30-40dB
Chirp ABR Correct Answers lower frequencies are sent a bit
earlier into the cochlea than the higher frequencies in order to
measure an ABR independent of the traveling wave delay
amplitude will increase because all of cochlear regions are
engaged at the same time
few sweeps needed
can get closer to threshold because the responses are so robust
that you can decrease intensity
CHL and LI function Correct Answers slope of LI function is
same as normal
shifted to the right with increasing loss
Chronic ME Otitis Correct Answers ABR elevated thresholds
Speech and Language delay
, Classification of evoked responses: Correct Answers Very
early, early, middle, late, very late- based on the latency of the
response
Common Mode Rejection Correct Answers you want high
CMR in your amplifier because the common stimulus
components will cancel and you you only measure the response
components
Condensation Correct Answers the response occurs a half a
cycle later- IV and V are more separated
Correcting for ILD of cochlear loss Correct Answers subtract
0.1 msec for every 10 dB of hearing loss above 50 dB at 4000
Hz
dB nHL Correct Answers the lowest SPL that you would get a
threshold for a particular stimulus
dB SPL (p.e. dB SPL) Correct Answers peak equivalent- set a
system to a value and measure the amplitude on an ossiciliscope
measure the peak voltage and then once you know the voltage
you introduce a 2-4 kHz tone and adjust the voltage of the tone
to be equivalent to the click and that level is called p.e. dB SPL
derived responses Correct Answers successive subtraction of
waves yields increasingly more apical region responses
greatest amplitude is around 500 Hz
takes a lot of time
A-D limits Correct Answers input signals cannot exceed the
voltage limits of the A-D converter
ABR Characteristics of CHL Correct Answers Absolute
latency of all components is prolonged in parallel fashion, so
IPLs are within normal limits
Absolute Latency Correct Answers time from the onset of the
stimulus to the peak of the response component
AC vs BC ABRs Correct Answers about 0.5 msec longer
latency for BC
infants more ABRs are seen with BC than AC at 30 dB nHL
BC latency does not change above 55 dB nHL
Amplitude Correct Answers (absolute) measure peak to trough
but we say peak to peak- we measure this way to reduce
variability due to baseline
Analog filtering Correct Answers changing the lower cut-ff and
upper cut-off frequencies
Analog section consists of what? Correct Answers Preamplifier
Differential amplifier
filtering of the signal
Gain added to the signal
At what time does digitizing begin? Correct Answers 0
,benefit of digital filtering Correct Answers doesnt create
distortions in amplitude or latency like analog filtering does
best stimulus to use for hearing status as a function of frequency
Correct Answers frequency specific tone burst
best stimulus when looking for site of lesion Correct Answers
clicks
Bone conduction ABR Correct Answers narrowband compared
to AC transducer
overall output is reduced
output decreasing with increasing frequency
threshold is elevated
limits dynamic range to 30-40dB
Chirp ABR Correct Answers lower frequencies are sent a bit
earlier into the cochlea than the higher frequencies in order to
measure an ABR independent of the traveling wave delay
amplitude will increase because all of cochlear regions are
engaged at the same time
few sweeps needed
can get closer to threshold because the responses are so robust
that you can decrease intensity
CHL and LI function Correct Answers slope of LI function is
same as normal
shifted to the right with increasing loss
Chronic ME Otitis Correct Answers ABR elevated thresholds
Speech and Language delay
, Classification of evoked responses: Correct Answers Very
early, early, middle, late, very late- based on the latency of the
response
Common Mode Rejection Correct Answers you want high
CMR in your amplifier because the common stimulus
components will cancel and you you only measure the response
components
Condensation Correct Answers the response occurs a half a
cycle later- IV and V are more separated
Correcting for ILD of cochlear loss Correct Answers subtract
0.1 msec for every 10 dB of hearing loss above 50 dB at 4000
Hz
dB nHL Correct Answers the lowest SPL that you would get a
threshold for a particular stimulus
dB SPL (p.e. dB SPL) Correct Answers peak equivalent- set a
system to a value and measure the amplitude on an ossiciliscope
measure the peak voltage and then once you know the voltage
you introduce a 2-4 kHz tone and adjust the voltage of the tone
to be equivalent to the click and that level is called p.e. dB SPL
derived responses Correct Answers successive subtraction of
waves yields increasingly more apical region responses
greatest amplitude is around 500 Hz
takes a lot of time
