Exam 2

Question 1

Explain how one or both cochleas may be responding when sound is presented via bone conduction. Explain how one or both cochleas may be responding when sound is presented via air conduction. (how can we get a response from the other cochlea)

Answer 1

During bone conduction, both cochleas is stimulated all at once.
with air, if it is high enough PL the other cochlea will respond. AC can activate bc mechanism

Question 2

List four important factors for soundfield testing. This question refers to making sure you conduct a valid test and is NOT asking about how to interpret your results.

Answer 2

Use a warble tone

Make sure the patient’s head aligns with the sticker in the booth for calibration

Make sure the patient is sitting at the correct azimuth to the speakers to which the booth was calibrated to

Make sure there are no reflections, like posters on the wall, that were not present during calibration

Question 3

How is test/retest reliability assessed? What amount of variation is acceptable for pure tone air conduction testing to be considered reliable?

Answer 3

For pure tone air conduction, plus or minus 5 dB is acceptable.

We start by testing the air conduction pure tones at 1,000 Hz and test up to 8,000 Hz. We then retest 1,000 Hz before we begin testing 250 Hz and finally 500 Hz.

Question 4

Can use when ear is impacted with cerumen

Answer 4

supra or circum

Question 5

Reduced occlusion effect

Answer 5

inserts

Question 6

Increased interaural attenuation

Answer 6

inserts

Question 7

Can use in case of atresia

Answer 7

supras or circum

Question 8

How would improper placement of insert earphones affect your testing? Two examples of improper placement of insert earphones would be shallow insertion, or using an insert that is too small for the ear canal. Name one example for full credit on this question. Name two examples that were discussed in class (one additional example) for one bonus point.

Answer 8

Improper placement of insert earphones will give us an increased threshold in the low frequencies. An example would be having an insert that is too small for the ear canal. This would cause some of the sound being transmitted into the ear canal to leak out of the ear instead of being sent down the ear canal like how it was calibrated to do with the correct distance from the tympanic membrane to the transducer.

Question 9

Define vibrotactile response. Is this more likely in lower or higher frequencies?

Answer 9

Vibrotactile response happens during bone conduction and is when the patient feels the vibrations instead of hears it. This occurs in the low frequencies.

Question 10

bony cochlea vibrates; traveling wave generated

Answer 10

distortional

Question 11

occluding ear “traps” sound in the ear canal, which transmits thorugh the tm

Answer 11

osseotympanic

Question 12

bony middle ear vibrates; ossicles are suspended and vibrate at the same frequency

Answer 12

inertial

Question 13

Describe the differences in frequency response for bone conduction vs. air conduction transducers. How do they differ in terms of the frequencies that can be tested and the limits of each one in terms of maximum amplitude at each frequency?

Answer 13

Air condution transducers have a broader frequency and you can have higher levels whereas bone conduction transducers is more limited. Bone conduction transducers is only able to test 250-4,000 Hz and air conduction transducers can test 250-8,000 Hz

Air conduction transducers can reach up to 120 dB where as bone conduction transducers have limits with 250 Hz at about 45dB, 500 Hz at about 60 dB and 1,000-4,000Hz at around 70 dB.

Question 14

For this question, dB is unspecified but the reference is the same throughout. The concept is the same whether it is dB SPL or dB HL.

A sound at location A is 75 dB, and it attenuates by 35 dB by the time it reaches location B.

What is the sound level at location B?

Would this sound be audible to someone with a hearing threshold of 35 dB for that sound?

Answer 14

Sound level at location B is 40 dB; it WOULD be audible to the listener

Question 15

Identify four potential consequences of incorrect masking.

Answer 15

Give the patient false hope

improper management, the patient receives surgery when they didn’t need it or they need the surgery but do not get it because of incorrect masking

incorrect levels for HA programming

lawsuit

Question 16

become less

Answer 16

attenuate

Question 17

non test ear hears sound presented to the test ear

Answer 17

cross hearing

Question 18

non test ear continues to respond despite use of masking

Answer 18

undermasking

Question 19

an increase of masking of certain dB with stimulus presented to the test ear remaining audible

Answer 19

plateau

Question 20

masking noise presented to NTE interferes with stimulus presented to the test ear

Answer 20

overmasking

Question 21

amount of dB in which a sound presented to the test ear is attenuated from test ear to the nte

Answer 21

interaural attenuation

Question 22

We use conservative interaural attenuation (IA) values based on studies measuring average IA values. What three factors influence the amount of IA that would actually be present?

Answer 22

the frequency

the transducer

the individual person

Question 23

When does our formula for the starting level of the masker include the occlusion effect?

Answer 23

When testing for bone conduction

Question 24

What question are we trying to answer when we mask for bone conduction?

Answer 24

if any hearing loss seen is conductive, mixed, or sensorineural
which cochlea was responding to our unmasked bone conduction testing
If a tone presented at one side via bone conduction crossed over and was heard at the other side