What are the initial steps when doing a hearing test?
Start with detailed history, then visual exam of outer ear (otoscopy) then determine test.
For a pure tone audiometry test, what do you start with?
start with air conduction and then try bone conduction.
What is the goal when doing pure tone audiometry test?
measure hearing threshold at each of the several frequencies
What AC frequencies are tested?
250, 500, 1000, 2000, 3000, 4000, 6000, 8000 (these are most important for speech)
What BC frequencies are tested?
500, 1000, 2000, 4000
What is the hearing threshold?
lowest level a person can hear 50% of the time`
What is the bracketing method?
“10 up; 5 down”
start by presenting tones at 30dB at 1000Hz. If patient hears that sound, decrease by 10dB. If patient does not hear, increase by 5 dB. Threshold is finally determined when patient responds to the lowest level 2/3 times, on an ascending pass
What is automated audiometry
Computer software that can test an individuals hearing with good accuracy.
Limited to cooperative adult patients
What does Red signify on an audiogram
right ear
When doing pure tone audiometry, what is important to note about Bone conduction?
- BC always stimulates both ears simultaneously
- AC will never be better than BC
- Comparison of BC and AC tells the type of hearing loss, but degree and configuration is based solely on AC.
- air bone gaps greater or equal to 15 dB are considered diagnostically significant
What does blue signify on an audiogram
left ear
What symbol is for AC unmasked right ear
circle
What symbol is for AC unmasked left ear
x
What symbol is for AC masked right ear
triangle
What symbol is for AC masked left ear
square
What symbol is for BC unmasked right ear
arrow pointing to the left
What symbol is for BC unmasked left ear
arrow pointing to the right
What symbol is for BC masked right ear
bracket facing to the left
What symbol is for BC masked left ear
bracket facing to the right
What will sensorineural hearing loss present itself like on an audiogram?
AC and BC thresholds are similar, both show a loss. No air bone gaps
What is the threshold on an audiogram that separates normal hearing from hearing loss
25 dB
What will conductive hearing loss present itself like on an audiogram?
air conduction threshold shows a loss bone conduction is in normal range. there is air bone gaps
What will mixed hearing loss present itself like on an audiogram?
air conduction thresholds and bone conduction thresholds both show a loss, but air is worse than bone
What is pure tone average
average threshold levels for each ear at 500, 1000, 2000
