Exam 1 Answers

Question 1

From the earliest appearing to latest appearing (in msec) what is the correct order of the major AEPs listed below:
ABR
ALR
AMLR
EcochG
P300
ECochG, ABR, AMLR, ALR, P300
ABR, ECochG, AMLR, ALR, P300
ABR, ECochG, ALR, AMLR, P300
P300, ECochG, ABR, AMLR, ALR
ECochG, P300, ALR, AMLR, ABR

Answer 1

ECochG, ABR, AMLR, ALR, P300

Question 2

Which of the following are TRUE regarding the click stimulus commonly used in AERs? Select ALL that apply.
A click has a rapid onset and wide bandwidth which stimulates a broad portion of the cochlea and causes many neurons to fire at one time
Because many neurons fire at one time, a click stimulus evokes a larger amplitude response than most tonal AER stimuli
Responses to click stimuli can be used in isolation to program hearing aids similar to behavioral thresholds on audiogram
The click has a long duration (slow rise and fall time) which makes it more frequency specific
A click contains energy from many frequencies but correlates best with thresholds in the 2000-4000 Hz range

Answer 2

A click has a rapid onset and wide bandwidth which stimulates a broad portion of the cochlea and causes many neurons to fire at one time
Because many neurons fire at one time, a click stimulus evokes a larger amplitude response than most tonal AER stimuli
A click contains energy from many frequencies but correlates best with thresholds in the 2000-4000 Hz range

Question 3

Which of the following statements are TRUE?
Toneburst or CHIRP stimuli are more frequency specific than a click because they are longer duration stimuli than a click
Toneburst or CHIRP stimuli are more frequency specific than a click because they are shorter duration stimuli than a click
Toneburst or CHIRP stimuli are less frequency specific than a click because they have more energy than a click
Toneburst or CHIRP stimuli are equivalent to a click stimulus when used appropriately
Toneburst or CHIRP stimuli have a shorter rise and fall time than a click and are therefore less frequency specific than a click

Answer 3

Toneburst or CHIRP stimuli are more frequency specific than a click because they are longer duration stimuli than a click

Question 4

Stimulus onset and offset (i.e., envelope) can affect AERs. Which of the following is the most commonly used envelope for AERs?
Blackman
Hanning
Hall
Picton
Trahan

Answer 4

blackman

Question 5

Polarity type where stimulus pressure wave moves toward the tympanic membrane first causing the stapes footplate to move toward the oval window and basilar membrane to move downward

Answer 5

condensation

Question 6

Polarity type where stimulus pressure wave moves away from the tympanic membrane first causing the stapes footplate to move away from the oval window and basilar membrane to move upward

Answer 6

rarefaction

Question 7

Polarity type where stimulus pressure wave is alternated on successive trials

Answer 7

alternating

Question 8

Has the earliest latency of the 3 polarity types

Answer 8

rarefaction

Question 9

Polarity used for ECochG and bone conduction testing

Answer 9

alternating

Question 10

Polarity type that can be split with split buffering feature yielding three responses for a single run

Answer 10

alternating

Question 11

Stimulus polarity type that reportedly produces the largest wave V amplitudes at low levels and may be better for estimating hearing threshold

Answer 11

condensation

Question 12

For auditory evoked responses, as a stimulus intensity decreases the latency of landmarks increases.

Answer 12

true

Question 13

For auditory evoked responses, as a stimulus intensity decreases, amplitude increases:

Answer 13

falsae

Question 14

For auditory evoked responses, as stimulus rate increases, latency of responses also increases slightly.

Answer 14

true

Question 15

For auditory evoked responses, as stimulus rate increases the amplitudes of earlier response components may decrease or become more difficult to identify.

Answer 15

true

Question 16

What are the two types of ABRs? Describe how you would perform each of them (i.e., what stimulus factors would you change and what would you leave alone) for each type? What would you look for when analyzing? Be brief but thorough.

Question 17

Which of the following is FALSE regarding ABR?
ABR is a test of hearing
The ABR response represents neural activity generated at several anatomic sites along the auditory pathway from the cochlea to the low brainstem
The ABR is characterized by up to 7 peaks or landmarks but we primarily focus on I-V
ABR may also be referred to as BAER
The later waveform peaks of the ABR most likely have multiple generators involved in the response

Answer 17

ABR is a test of hearing
Note: False. ABR is a test of neural synchrony. We can infer hearing from it but hearing involves cortical perception of sound and we are only testing to low brainstem

Question 18

Match the ABR landmarks (waves) with the appropriate generators in teh auditory pathway
WAVE I, II, III, IV, V

Answer 18

Wave I - distal VIII N (spiral ganglion)
Wave II - Proximal portion of the 8 n with some contribution from distal 8 n
Wave III - cochlear nucleus and fibers entering the cochlear nucleus
Wave IV - superior olivary complex most likely w/ possibly some contribution from lateral lemniscus and inferior colliculus
Wave V - multiple generators but primarily lateral lemniscus and inferior colliculus

Question 19

Absolute latency is the most robust and reliable parameter and provides the mainstay for interpreting ABR responses.

Answer 19

true

Question 20

At what age does ABR become adult-like?
2 - 3 years of age
1 year of age
The ABR is adult-like at birth
5 years of age
13 years of age

Answer 20

2-3urs

Question 21

List 3 reasons why you might perform a rate study (neurologic) ABR?

Answer 21

1. Unexplained asymmetry in thresholds of non-conductive nature
2. Elevated or absent ME muscle reflex or abnormal reflex decay
3. Poor word recognition score in quiet (relative to audiogram)
4. Unexplained dizziness/vertigo
5. Unilateral tinnitus
6. PI-PB Rollover on speech testing
7. Sudden Hearing loss of unknown cause
8. Poor inter-test reliability (tests don’t match)
9. To aid in diagnosis of demyelinating conditions (MS) or in ANSD

Question 22

List 2 reasons why you might perform a threshold ABR?

Answer 22

(1)Suspected non-organic hearing loss
(2) Poor inter-test agreement on behavioral testing
(3)Inability to test with conventional methods (newborn, handicapped, etc)
(4)For amplification fitting purposes on special populations (young children, handicapped, dementia, etc)

Question 23

As hearing loss increases wave I amplitude typically increases?

Answer 23

False

Question 24

If you cannot easily identify wave I on your ABR, which of the following strategies could be employed to help you better isolate the landmark or obtain a larger amplitude?
Run an ECochG and look for correlation between AP of the ECochG and wave I of the ABR as they are the same generators
Increase your stimulus intensity
Decrease (slow) your rate
Utilize a different electrode montage (closer to generator site) such as an in the canal (tymp/tiptrode) array
All of these are correct

Answer 24

all

Question 25

Auditory evoked responses in infants mature in the medial to distal direction (i.e., cortical responses mature before brainstem responses which mature before cochlear/VIlIth nerve processes

Answer 25

false

Question 26

If you have noise (artifact) in your EP recordings, list 3 things you can try to improve them.

Answer 26

* Tightly braid electrode leads (leads short as possible) * Impedance equals 5 kohms or less * Make sure amp cable not crossing over stimulus cable * Amp at least 3 feet away from the base * Increase number of averages * Turn off "noise checking" * Try another room and/or outlet * Make sure patient is comfortable and breathing slowly out of mouth

Question 27

What is the difference between a click stimulus and the CE chirp stimulus?

Answer 27

The click is a broadband stimulus that contains energy at many frequencies. When presented, it activates the entire basilar membrane but because of the tonotopic organization of the cochlea and the traveling wave, it activates each frequency region of the cochlea at different times. The CE-Chirp takes the tonotopic organization of the cochlea into consideration and is engineered to adjust the timing of the frequencies presented to the ear. The low frequencies of the stimulus are presented before the high frequencies to correct for the traveling wave delay. This adjustment results in more synchronous firing because all the frequency regions of the cochlea are stimulated at the same time. The result is an ABR response that is 1.5 - 2 times larger than the click ABR. Chirp can be broadband or NB. Difference is timing of stimulus components (race analogy I talked about) Chirp can be broadband or NB. Difference is timing of stimulus components (race analogy I talked about)

Question 28

ABR thresholds do not equate to pure-tone thresholds. You must apply a correction factor from Toneburst or Chip thresholds obtained from ABR to correlate them with frequency specific pure-tones.

Answer 28

true

Question 29

Which of the following is FALSE for an ABR performed at a high intensity level (80-90 dBnHL)? The approximate latency for wave I of the ABR is 0.5 msec Note: The approximate latency for wave I of the ABR is 1.5 msec The approximate latency for wave Ill of the ABR is 3.5 msec The approximate latency for wave V of the ABR is 5.5 msec The approximate I-III and III-V interpeak latencies are 2.0 msec

Answer 29

The approximate latency for wave I of the ABR is 0.5 msec

Question 30

Which of the following are TRUE regarding masking for AERs. Select ALL that apply. If wave l is present at normal latency you do NOT need masking If wave V is delayed and stimulus intensity is greater than 70 dB nHL (or minimum IA value) then contra-lateral masking is required for AC testing. The minimum inter-aural attenuation for insert earphones is 40 dB nHL Masking is not required for ABR testing because we are measuring brainstem responses If you utilize supra-aural headphones you will need to mask far less often than with insert earphones due to better (larger) IA values

Answer 30

If wave l is present at normal latency you do NOT need masking If wave V is delayed and stimulus intensity is greater than 70 dB nHL (or minimum IA value) then contra-lateral masking is required for AC testing.

Question 31

Which of the following statements about stacked ABR is TRUE? Stacked ABR is a technique that sought to better identify small tumors (<1cm) though it is not in routine clinical practice today Stacked ABR can be used to differentiate types of tumors (e.g., meningioma from acoustic neuroma from gliomas) Stacked ABR can be used to identify tumors above the brainstem in the cortex Stacked ABR is a rapid way to test newborn babies for presence of hearing loss Stacked ABR is performed by doubling up or "stacking" electrodes to generate a more sensitive response

Answer 31

Stacked ABR is a technique that sought to better identify small tumors (<1cm) though it is not in routine clinical practice today

Question 32

A normal bone-conducted click or tone burst ABR would show missing wave(s) ________ with normal wave V

Answer 32

I-III

Question 33

The CE-Chirp stimulus was named after the inventor / researcher who developed it. What was his name (initials are C.E.).

Answer 33

Clause Elberling

Question 34

Which of the following is credited with first describing ABR/BAER? Jewett and Williston Einthoven and Florey David Kemp House and Brackmann Robert Barany

Answer 34

Jewett and Williston

Question 35

In what decade were these auditory "bumps" first described? 1970s 1990s 1950s 1920s 1930s

Answer 35

1970s