Reading an audiogram

1. Reading an Audiogram

2. Air vs. Bone Conduction
 A/C
 Via TDH-50P headphones
 Placed on Pinna
 Checks the validity of
entire ear system
 Tests that ipsilateral ear
 B/C
 Bone vibrator
 Placed on Mastoid Process
 Tests the validity of only the
inner ear
 Tests better cochlea

3. Things to know about an Audiogram
Lo to Hi Frequency (abscissa)
 125 Hertz to 8000 Hertz
 Octave and half-octaves
Lo to Hi dB (ordinate)
 -10 dB HL to 120 dB HL
Each dB is equal to one octave
It is a Legal document
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4. The Legend

5. Ranges of Hearing Loss
 -10 – 25 dB HL = Normal range
 26 – 40 dB HL = Mild hearing loss
 41 – 55 dB HL = Moderate

 56 – 70 dB HL = Moderately Severe
 71 – 90 dB HL= Severe
 Greater than 90 dB HL = Profound

6. Normal Hearing

7. Conductive Hearing Loss

8. Sensorineural Hearing Loss

9. Mixed Hearing Loss

10. Other “Hearing” Tests
Tympanometry
Acoustic Reflexes
Speech Audiometry
 Speech Reception Threshold (SRT)
 Speech Discrimination (SD)
ABR
ECOCHG (Electrocochleography)
OAE

11. What about Hearing Aids
Minimal hearing loss
 Probably no/little benefit
Moderate hearing loss and usually
sensorineural hearing loss are good
candidates
Profound hearing loss?
 Could for environmental & safety reasons
 Cochlear Implant