Hearing Flashcards
What are the two aspects of the ossicles that amplify sound?
- Ratio of the SA of the TM to the footplate of the stapes
- Lever action of the ossicular chain
What are the two aspects of the outer ear that amplify sound?
- Shape of the auricle
- Resonance of the ear canal
Where is high frequency sound heard in the basilar membrane? Low?
High = beginning Low = end
What are the three vestibuli of the cochlea?
Scala tympani
Scala media
Scala vestibuli
What comprises the “cochlear microphone”?
Efferent nerve signals from the organ of corti
Is measuring the cochlear effects on EEG via the auditory brainstem response a measure of hearing?
No–hearing is a subjective perception
What is the gold standard for measuring hearing?
Behavioral testing
What is measured with behavioral hearing testing? (3)
- Hearing level
- Speech reception threshold
- Speech discrimination / word recognition
What is the age at which you can begin auditory testing on a kid? How?
- 6 months
- play therapy and visual reinforcement
What, generally, is an audiogram?
Nomogram of hearing for select frequencies designed to best reflect hearing necessary for language
True or false: a 0 decibel hearing level equates to the lack of acoustic energy
False–0 is the log of 1
What is the scale that is used to measure normative frequencies?
Logarithmic
Any hearing below what log value is normal?
20
What is conductive hearing loss?
Conductive hearing loss occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane (eardrum), or middle ear (ossicles).
What is sensorineural hearing loss?
a type of hearing loss, or deafness, in which the root cause lies in the inner ear or sensory organ (cochlea and associated structures)or the vestibulocochlear nerve (cranial nerve VIII)or neural part
What is the federal mandate in terms of treating kids with hearing loss?
Must identify and treat by 6 months of age
What is an otoacoustic emission test, in terms of what is being tested?
A test to indicate that cochlear function is intact, but not a hearing test
Is the brain maximally stimulated: noise or quiet?
quiet
What are the limitations of an OAE?
- Very high false positive rate
- Emissions can be absorbed with canal debris (meconium)
How are the limitations of the OAE overcome?
Repeated until positive
What is measured with an auditory brainstem response?
EEG at different sites in the brainstem, with different frequencies