1 - Masking

Question 0

When is masking necessary?

Answer 0

During air conduction: when we cannot be sure that we are actually testing the ear we think we are testing due to the cross over effect

During bone conduction: when we are not sure if the problem is with the outer and/or middle ears or that of the cochlea and/or nervous system

Question 1

What is masking?

Answer 1

Masking is a process where the threshold of audibility is raised by the presence of a second sound

Question 2

What is Interaural Attenuation?

Answer 2

A decrease in a signal’s intensity as it passes from one ear to the other

Question 3

Interaural Attenuation values will vary due to __________ and the __________.

Answer 3

Frequency of the signal

Transducer being used (Bone, insert earphones, etc.)

Question 4

When using bone conduction, the signal reaching the cochlea _________.

Answer 4

Is approximate the same in both ears

Question 5

Without masking, a bone conduction signal may be heard by ________.

Answer 5

The right, the left, or both ears

Question 6

When unmasked, bone conduction thresholds are determined by _________.

Answer 6

The better ear

Question 7

How does the signal cross the head during air conduction?

Answer 7

Via bone conduction

Question 8

When do you need to mask during air conduction?

Answer 8

When there is a 40 dB difference between the threshold of the right ear versus that of the left

Question 9

If one or both ears hears in a normal range then ___________.

Answer 9

We assume that the bone conduction levels will match that ear

Question 10

What is the lowest interaural attentuation at which crossover might occur?

Answer 10

40 dB

Question 11

Is masking ever used during speech audiometry testing?

Answer 11

Yes

Question 12

Why are insert headphones preferred by audiologist?

Masking Version

Answer 12

They provide for a larger interaural attenuation value

This means less masking dilemmas

Question 13

What is a shadow curve?

Answer 13

When the hearing threshold curve of a poor to nonfunctioning ear mirrors that of the better ear

This usually means that the better ear is hearing the signal and making the poorer ear seem better than it actually is

Question 14

When you see a shadow curve, you need _____.

Answer 14

To mask

Question 15

What sort of noise is usually used for masking?

Answer 15

Narrowband Noises

Question 16

What is white noise?

Answer 16

A random and equal representation of all frequencies of equal intensity

Question 17

What is narrowband noise?

Answer 17

Filtered white noise where the center frequency is the test signal

Question 18

What is speech weighted noise?

Answer 18

Similar to white noise but shaped to mirror the frequency spectrum of speech

Question 19

During a hearing test, what do we call it when a sound is intense enough to be relayed to the opposite ear via bone conduction?

Answer 19

Cross Over Effect

Question 20

When does the cross over effect occur most often?

Answer 20

During bone conduction

Question 21

The cross over effect makes it hard to test _____ and _____.

Answer 21

Hearing sensitivity

Sensorineural sensitivity

Question 22

What sorts of noises can be used for masking?

3

Answer 22

White Noise

Narrowband Noise

Speech Weighted Noise

Question 23

What does white noise sound like?

Answer 23

Static

Question 24

When is speech weighted noised used when masking?

Answer 24

During speech audiometry

Question 25

When does interaural attenuation occur?

Answer 25

When sound that is transmitted by either air or bone conduction to the test ear that arrives at the opposite ear via bone conduction

Question 26

What is attenuation?

Answer 26

A decrease in intensity

Question 27

What is a masked threshold?

Answer 27

The threshold of audibility for a specific sound in the presence of another sound (masker)

Question 28

What is a masker?

Answer 28

An sound whose prescence raises the threshold of audibility of another sound

Question 29

When there is a difference between bone conduction and air conduction of ________, masking is necessary

Answer 29

10 dB in the same ear

Question 30

When there is a difference in air conduction levels between the right and left ears of ________, masking is necessary.

Answer 30

40 dB between the two ears

Question 31

The masking level used in clinical audiometry should never be _____ than the ______ of _______.

Answer 31

Less Air conduction threshold The ear being masked

Question 32

What is the minimum masking level?

Answer 32

When the masker is at a level just sufficient enough to mask the test signal

Question 33

What is the maximum masking level?

Answer 33

The highest level a masker can be introduced into the non-test ear without over masking

Question 34

What is overmasking?

Answer 34

When the masker crosses into the test ear making the test ear's threshold poorer

Question 35

If the Bone Conduction Level is _____ than the Air Conduction Level in ______ then you will need to use masking to find the threshold for ______ in that ear.

Answer 35

10 dB better The same ear Bone conduction

Question 36

If the Air Conduction Level in one ear is _____ than ______ then you will need to use masking to find the threshold for ______ in ______ ear.

Answer 36

40 dB The Air Conduction Level in the opposite ear Air Conduction The poorer

Question 37

Which ear is masked?

Answer 37

The non-test ear The test ear can also be masked but this is not usually done in clinical situations