Bone Conduction Hearing

Question 1

Describe the bone conduction hearing mechanisms

Question 2

How does osseo tympanic mechanism impact hearing?

Question 3

How does inertial mechanism come into play?

Question 4

How do different pathologies impact bone conduction thresholds?

Question 4

How does the bone oscillator placement impact test results?

Question 5

T/F: During skull vibrations, cochlear capsule alternates between compression and expansion, which displaces the basilar membrane

Answer 5

True

Question 6

During skull vibrations, the distortion of the cochlear capsule displaces the basilar membrane

Answer 6

True

Question 7

During skull vibration, the oval window and round window serve as the primary outlets for cochlear fluid displacement or “pressure vents”

Answer 7

True

Question 8

The cochlear fluid displacement during vibrations is inhibited when the vestibular aqueduct is enlarged

Answer 8

True

Question 9

Inertial lag in the inner ear comes from the cochlear fluids and the spiral lamina

Answer 9

True

Question 10

The mastoid placement of the bone oscillator enables testing of the ear on the side the oscillator is placed, without contamination from the opposite ear

Answer 10

True

Question 11

How does the outer ear contribute to bone conduction hearing?

Answer 11

Radiation from the ear canal propagates through the middle ear which increases the audibility of the bone conducted sound

Question 12

The phenomenon where the audibility of bone conducted signal is enhanced when the vibrator is placed at the mastoid but not when it is placed at the midline _______________.

Answer 12

Is due to inertial lag of the middle ear ossicles and is most prominent at 2000 Hz

Question 13

What is the Carhart notich?

Answer 13

A phenomenon that occurs only when the bone oscillator is placed at the mastoid

Question 14

T/F: Otitis media with effusion may cause bone conduction thresholds to elevate (need more intensity to be audible)

Answer 14

True

Question 15

T/F: Otosclerosis causes sensory hearing loss at 2000 Hz

Answer 15

False

Question 16

T/F: Middle ear pathologies inhibits AC sound from reaching the cochlea, but does not change the transmission of the BC sound

Answer 16

False

Question 17

T/F: Middle ear disorders can cause ABGs as great as 80 dB

Answer 17

False

Question 18

PseudoSNHL from intracranial hypertension tend to be in the __________ frequencies.

Answer 18

Low

Question 19

T/F: The dynamic range of BC testing is greater when the oscillator is placed at the mastoid as opposed to the forehead

Answer 19

True

Question 20

T/F: Vibrotactile responses occur at a lower intensity when presenting AC stimuli compared to BC stimuli

Answer 20

False

Question 21

T/F: Vibrotactile responses occur at a lower intensity level for 500 Hz tone compared to 1000 Hz tone

Answer 21

True

Question 22

What is Carhart’s notch?

Answer 22

Bone conduction threshold that is depressed (notched) at 2k Hz compared to adjacent frequencies.

Suggests presence of otosclerosis.

BC threshold does not represent a close-to-accurate sensitivity of cochlear hearing.

Question 23

T/F: Otitis media with effusion can cause enhancement of BC thresholds

Answer 23

True

Question 24

T/F: Enhancement of BC thresholds due to occlusion effect is observed only in low frequencies

Answer 24

True

Question 25

T/F: Enhancement of BC thresholds due to occlusion effect is especially pronounced when using insert earphones

Answer 25

False

Question 26

T/F: Superior canal dehiscence presents with falsely depressed BC thresholds; in some cases, BC thresholds may be greater than AC thresholds

Answer 26

False