Chp.4: Pure Tone Bone Conduction Audiometry And Masking

Front 1

What are the 3 phenomena of Bone Conduction mechanisms? ( phenomena that makes us hear when we present sound through BC)

Back 1

1. distortional bone conduction
2. inertial bone conduction
3. osseotympanic bone conduction

Front 2

Which phenomena does this description explain? "skull is moving, ossicles lag behind, due to intertia, stapes moves relative to oval window, stimulates cochlea"

Back 2

inertial bone conduction

Front 3

Which phenomena does this description explain? "vibration of the column of air in the outer ear, follow same route as AC waves

Back 3

osseotympanic bone conduction

Front 4

Which phenomena does this description explain? "distorton of the structures in the cochlea, give rise to stimulation of inner ear, same as an AC signal stimulates the cochlea"

Back 4

Distortional Bone conduction

Front 5

Is masking imperative during the bone conduction procedure? If yes, then why?

Back 5

Yes Masking is imperative because both of the cochlea are stimulated. Since they are both stimulated, it is hard to figure out which ear to test.

Front 6

What are the 3 phenomena of Bone Conduction mechanisms? ( phenomena that makes us hear when we present sound through BC)

Back 6

1. distortional bone conduction
2. inertial bone conduction
3. osseotympanic bone conduction

Front 7

Which phenomena does this description explain? "skull is moving, ossicles lag behind, due to intertia, stapes moves relative to oval window, stimulates cochlea"

Back 7

inertial bone conduction

Front 8

Which phenomena does this description explain? "vibration of the column of air in the outer ear, follow same route as AC waves

Back 8

osseotympanic bone conduction

Front 9

Which phenomena does this description explain? "distorton of the structures in the cochlea, give rise to stimulation of inner ear, same as an AC signal stimulates the cochlea"

Back 9

Distortional Bone conduction

Front 10

Is masking imperative during the bone conduction procedure? If yes, then why?

Back 10

Yes Masking is imperative because both of the cochlea are stimulated. Since they are both stimulated, it is hard to figure out which ear to test.

Front 11

Why is there limited maximum output for bone conduction testing?

Back 11

Because sending sound vibrations to the cochlea by way of the skull requires more intensity, so the intensity levels the audiometer can produce at different frequencies for bone conduction are less than those for air conduction tones

Front 12

What are two placements for bone conduction testing?

Back 12

forehead and mastoid

Front 13

Which placement for Bone conduction does this describe, "easier to place, less variation to skull pressure, test retest differences"

Back 13

forehead placement

Front 14

Which placement for Bone conduction does this describe, "less energy/vibration to reach threshold, proximity to TE, convenient for masking"

Back 14

mastoid placement

Front 15

What is masking?

Back 15

Noise used to eliminate participation of one ear while the opposite ear is being tested

Front 16

What is the second definition of masking?

Back 16

the amount by which the threshold of audibility of a sound is raised by the presence of another (masking sound)

Front 17

What are two main concepts involved with masking that Goldstein and Newman (1994) claim are important?

Back 17

1. a second signal is introduced that interferes with the primary (test)signal
2. a shift in threshold generally occurs

Front 18

Why us it necessary to eliminate the non test ear?(because of what type of hearing loss?)

Back 18

because of asymmetrical hearing loss where the air conduction responses from each ear do not hear the same so the better ear may be hearing tones presented to the poorer ear

Front 19

Is masking necessary in symmetrical hearing loss?

Back 19

NO because air conduction thresholds are the same in both ears

Front 20

Which type of band noise is used for masking and why?

Back 20

narrow band noise because it is centered around the frequency of interest and has a restricted bandwidth

Front 21

What does the critical band concept state?

Back 21

the only parts of the noise that have a masking effect on the test tone lie withing a restricted band with the test tone at its center

Front 22

Why is white noise not used for masking?

Back 22

Because it is a wider band spectrum and does not increase masking effect. Instead it adds to the overall loudness

Front 23

When providing instructions to the patient, what two thing should you tell them to do?

Back 23

1. ignore the noise in the NTE
2. respond when the tone is heard

Front 24

What is effective masking?

Back 24

the dB HL to which threshold is shifted by a given level of noise

ex. 30 dB EM shifts pure tone AC sound to 30 dB HL

Front 25

What is interaural attenuation?

Back 25

reduction in the energy of the signal as it is transmitted from one side of the skull to the other

Front 26

What is the recommended minimum interaural attention for air conduction when wearing supra-aural headphones?

Back 26

40 dB HL

Front 27

What is the recommended minimum interaural attention for air conduction when wearing insert headphones?

Back 27

50 dB HL

Front 28

Is cross hearing possible? If so, how?

Back 28

Yes it is possible given a set of circumstances. Generally involves different hearing between the client's ears.

Front 29

What does ACT(TE)-IAA(40dB/50dB)>BCT( NTE) mean?

Back 29

if air conduction threshold (ACT) of the test ear minus the minumum interaural attenuation (40 dB HL) is greater than or equal to the bone conduction threshold (BCT) of the non test ear, then masking is needed to occupy the non test ear

Front 30

When should we mask during Bone conduction?

Back 30

most of the time

Front 31

What is the interaural attentuation for BC signals?

Back 31

0 dB HL; the head doesn't block any of the signal from reaching one cochlea or the other

Front 32

What does ABG (TE)>10 mean?

Back 32

Whenever there is an air-bone gap greater than 10 dB, then mask non test ear during bone conduction testing

Front 33

What method does this describe?
"introduce the noise and re-establish the threshold in the test "?

Back 33

Plateau method

Front 34

if the threshold is unchanged during masking, then this is the....

Back 34

true threshold of the test ear

Front 35

IF there is a shift in threshold by 5 dB, then search from the true threshold by...

Back 35

raising the masking noise by 10 dB

Front 36

IF the threshold shifts by more than 5 dB then...

Back 36

the procedure is repeated

Front 37

The true threshold must remain stable over a plateau of...

Back 37

20 dB when masking level is raised

Front 38

When is overmasking considered?

Back 38

when the masking sound in the NTE is so intense, it crosses over to the TE

Front 39

When should the occlusion effect be considered?

Back 39

during bone conduction testing of lower frequencies in individuals with normal hearing or SNHL

Front 40

What does the occlusion effect imply?

Back 40

an improvement( decrease) in the bone conduction of tones of 1000Hz or less when ears are tightly covered with an earphone during BC testing

Front 41

Can bone conduction thresholds be worse than air conduction?

Back 41

Yes

Front 42

What are some reasons BC thresholds could possibly be worse than AC thresholds?(4 reasons)

Back 42

1. middle ear system influences BC signal
2. Variability in behavioral tasks
3. inter and intra-person differences
4. calibration or unreliable responses

Front 43

What are four pitfalls of pure tone testing?

Back 43

1. false negatives and false positives
2. collapsing ear canal
3. standing waves
4. tactile responses

Front 44

What does false negative imply?

Back 44

when client fails to respond even when hearing the tone

Front 45

What does false positive imply?

Back 45

when client responds when on tone has been presented

Front 46

What are 4 solutions to a collapsed ear canal?

Back 46

1. testing in sound field
2. repositioning ear phones
3. using material such as foam
4. using insert earphones

Front 47

At what frequency does a standing wave usually occur?

Back 47

8000 Hz

Front 48

What are 2 solutions for a standing wave?

Back 48

1. repositioning of the supra-aural earphones
2. use of insert earphones

Front 49

What type of hearing loss and what type of frequencies do tactile responses usually occur?

Back 49

1. severe hearing loss
2. low frequencies (250,500)