Bone Conduction Hearing Flashcards
Describe the bone conduction hearing mechanisms
How does osseo tympanic mechanism impact hearing?
How does inertial mechanism come into play?
How do different pathologies impact bone conduction thresholds?
How does the bone oscillator placement impact test results?
T/F: During skull vibrations, cochlear capsule alternates between compression and expansion, which displaces the basilar membrane
True
During skull vibrations, the distortion of the cochlear capsule displaces the basilar membrane
True
During skull vibration, the oval window and round window serve as the primary outlets for cochlear fluid displacement or “pressure vents”
True
The cochlear fluid displacement during vibrations is inhibited when the vestibular aqueduct is enlarged
True
Inertial lag in the inner ear comes from the cochlear fluids and the spiral lamina
True
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
True
How does the outer ear contribute to bone conduction hearing?
Radiation from the ear canal propagates through the middle ear which increases the audibility of the bone conducted sound
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 _______________.
Is due to inertial lag of the middle ear ossicles and is most prominent at 2000 Hz
What is the Carhart notich?
A phenomenon that occurs only when the bone oscillator is placed at the mastoid
T/F: Otitis media with effusion may cause bone conduction thresholds to elevate (need more intensity to be audible)
True
T/F: Otosclerosis causes sensory hearing loss at 2000 Hz
False
T/F: Middle ear pathologies inhibits AC sound from reaching the cochlea, but does not change the transmission of the BC sound
False
T/F: Middle ear disorders can cause ABGs as great as 80 dB
False
PseudoSNHL from intracranial hypertension tend to be in the __________ frequencies.
Low
T/F: The dynamic range of BC testing is greater when the oscillator is placed at the mastoid as opposed to the forehead
True
T/F: Vibrotactile responses occur at a lower intensity when presenting AC stimuli compared to BC stimuli
False
T/F: Vibrotactile responses occur at a lower intensity level for 500 Hz tone compared to 1000 Hz tone
True
What is Carhart’s notch?
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.
T/F: Otitis media with effusion can cause enhancement of BC thresholds
True
T/F: Enhancement of BC thresholds due to occlusion effect is observed only in low frequencies
True
T/F: Enhancement of BC thresholds due to occlusion effect is especially pronounced when using insert earphones
False
T/F: Superior canal dehiscence presents with falsely depressed BC thresholds; in some cases, BC thresholds may be greater than AC thresholds
False
