Masking (final exam)

Question 1

Define Masking

Answer 1

The process by which the threshold of a sound is elevated by the simultaneous introduction of another sound

Question 2

The process by which the threshold of a sound is elevated by the simultaneous introduction of another sound

Answer 2

Masking

Question 3

Is masking used in evaluation?

Answer 3

Yes

Question 4

Is masking used in screening?

Answer 4

No

Question 5

Why is masking used?

Answer 5

To prevent the non-test ear from participating in the evaluation of the test ear

Question 6

Masking is only used in…

not referring to evaluation/screening

Answer 6

Audiometry

Question 7

The amount by which the air conduction threshold exceeds the bone conduction threshold at a particular frequency in the same ear.

Answer 7

Air-bone gap

Question 8

Explain air-bone gap

Answer 8

The difference between air and bone conduction thresholds.

Question 9

When should you mask?

Answer 9

When the ABG is greater than 10 in one ear then masking is probably needed in the other ear.

Question 10

What are the 3 questions audiologists ask for masking?

Answer 10

Is masking needed?
If so, how much masking should we use?
At what point did we put too much noise?

Question 11

What is interaural attenuation?

Answer 11

Number of decibels lost in cross hearing
or
the loss of energy of a sound presented by AC (air conduction) or BC (bone conduction) as it travels from the test ear to the non-test ear.

Question 12

What is the interaural attenuation with sura-aural headphones?

Answer 12

40dBHL

Question 13

What is the interaural attenuation with insert earphones in low frequencies?

Answer 13

75dBHL

Question 14

What is the interaural attenuation with insert earphones in higher frequencies?

Answer 14

50dBHL

Question 15

What is the interaural attenuation with bone conduction?

Answer 15

0dBHL

Question 16

T/F cross hearing is not possible with bone conduction

Answer 16

False, cross hearing is always possible with bone conduction because the IA is 0dBHL

Question 17

When do we need to mask pure tones?

Answer 17

AC (air conduction) of the Test Ear minus the Interaural Attenuation is greater than or equal to the BC (bone conduction) of the Non-Test Ear.

Air-Bone Gap of the Test Ear is greater than 10dBHL

Should also look at the AC of the Test Ear and AC of the Non-Test ear to determine if the Interaural attenuation has been exceeded

Question 18

Are you less likely to mask with insert earphones or supra-aural earphones? Why?

Answer 18

You are less likely to mask with insert earphones because they provide greater separation between the ears.

Question 19

Two types of masking noise are..

Answer 19

speech noise and narrow band noise

Question 20

Which is more effective, speech noise or narrow band noise?

Answer 20

Speech noise

Question 21

Explain speech noise for masking

Answer 21

Broadband; used to mask speech stimuli; sounds like hissing

Question 22

Explain narrow band noise for masking

Answer 22

band pass filtering of broadband noise; small band of frequencies surrounding a frequency to be masked; used to mask pure tones

Question 23

What is effective masking?

Answer 23

Minimal amount of noise required to just mask out a signal at a given hearing level

Question 24

Explain central masking

Answer 24

a small pure tone threshold shift occurring when masking is presented to the opposite ear.

You do not want this.

Question 25

List the three masking methods

Answer 25

Shotgun approach, minimum noise method, plateau method.

Question 26

How do you mask for speech audiometry?

Answer 26

compare the speech recognition threshold of the test ear to the best bone conduction threshold of the non-test ear with interaural attenuation factored in