BAERs Flashcards
dB SPL
Sound Pressure Level
Based on a physical measure of sound pressure relative to atmospheric pressure
dB HL
Hearing Level
hearing threshold of a population, sound intensity relative to average threshold of hearing for normal listeners
0dB HL is threshold of the normal pop.
dB nHL
Normal Hearing Level
sound intensity relative to the average threshold of a bunch of your friends
*same as HL, but machine is calibrated according to a small local population
dB SL
Sensation Level
an individual’s personal threshold, sound intensity relative to a listener’s own threshold of hearing
0dB SL=the subject’s hearing threshold
dB peSPL
Peak Equivalent SPL
used for complex signals such as click sounds-amplitude of click measured by oscilloscope is compared to pure tone of a known dB SPL value… when click and pure tone have the same value, the click is “peak equivalent” SPL
1000Hz of pure tone is typically used
Condensation
Positive pressure click, moves tympanic membrane inward
Rarefaction
negative pressure click, moves tympanic membrane outward
Alternating click polarity
both condensation and rarefaction clicks alternated
What is the auditory pathway?
auditory nerve>cochlear nuclei>superiorolivary complex>lateral lemniscus>inferior colluculus>medial geniculate body/thalamus>auditory cortex
What is the anatomic generator of wave I?
the distal auditory nerve
What is the anatomic generator of wave II?
exit of potential from IAC where nerve enters fluid from bone
What is the anatomic generator of wave III?
cochlear nucleus (or superior olivary complex)
What is the anatomic generator of wave IV?
Lateral lemniscus (or superior olivary complex)
What do we monitor for a choleasteatoma?
Facial nerve since it runs through the middle ear cavity
*choleasteatoma=disease of the ear which a skin cyst grows into the middle ear and mastoid
What is a mastoidectomy?
Surgery performed in the mastoid, where disease may occur
we monitor BAERs and facial nerve?
