Reading an Audiogram Air vs Bone Conduction l
Reading an Audiogram
Air vs. Bone Conduction l A/C ¡ Via TDH-50 P headphones l Placed on Pinna l B/C ¡ Bone vibrator l Placed on Mastoid Process ¡ Checks the validity of entire ear system ¡ Tests the validity of only the inner ear ¡ Tests that ipsilateral ear ¡ Tests better cochlea
Things to know about an Audiogram l Lo to Hi Frequency (abscissa) ¡ 125 Hertz to 8000 Hertz ¡Octave and half-octaves l Lo to Hi d. B (ordinate) ¡-10 d. B HL to 120 d. B HL l Each 20 d. B is equal to one octave l It is a Legal document
The Legend
Ranges of Hearing Loss l -10 – 25 d. B HL = Normal range l 26 – 40 d. B HL = Mild hearing loss l 41 – 55 d. B HL = Moderate l l 56 – 70 d. B HL = Moderately Severe l 71 – 90 d. B HL= Severe l Greater than 90 d. B HL = Profound
Normal Hearing
Conductive Hearing Loss
Sensorineural Hearing Loss
Mixed Hearing Loss
Other “Hearing” Tests l Tympanometry l Acoustic Reflexes l Speech Audiometry ¡ Speech Reception Threshold (SRT) ¡ Speech Discrimination (SD) l ABR l ECOCHG (Electrocochleography) l OAE
What about Hearing Aids l Minimal hearing loss ¡Probably no/little benefit l Moderate hearing loss and usually sensorineural hearing loss are good candidates l Profound hearing loss? ¡Could for environmental & safety reasons ¡Cochlear Implant
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