Download How we DON*T Hear

How we DON’T Hear
Types of Hearing Loss, How they
Happen, and What can be Done
about Them
How Does a Person Hear?
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http://www.earinfo.com/howread1.html
What are the “Levels of
Deafness”?
Types of Hearing Tests
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Air Conduction
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Standard hearing screen
Uses “headphones”
Bone Conduction
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Standard hearing test
includes this
Uses a “bone conductor
headphone”
Conductive Hearing Loss
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Occurs in the external or middle ear
Can be caused by a number of reasons:
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Closed external auditory meatus
Blocked EAM from wax, debris, tumors
Damaged tympanic membrane
Damaged ossicles
Otitis Media (Ear Infection)
Other problems
Conductive Loss: How Much?
How Can it be Fixed?

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A conductive loss is up to 60 dB
Most of the time it can be medically
corrected, either through drugs or surgery
Sensorineural Loss
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Occurs in the Inner Ear (cochlea, auditory
nerve, or the brain)
Can be caused by a number of reasons:
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Age
Illness (high fever, lack of oxygen)
Medicines
Loud Noises
Tumors
Sensorineural Loss: How
Much? How Can it be Fixed?
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A sensorineural loss can be
complete (beyond 120 db)
It can NEVER be fixed
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A hearing aid can amplify what is
being heard, but cannot correct
the hearing
A cochlear implant can be
surgically implanted to restore a
“hearing-like” sensation, but does
not sound like normal hearing
90% of hearing loss is in
this category
Mixed Loss
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A combination of a conductive loss and a
sensorineural loss
Can be caused by a number of reasons:
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Medicinally damaged cochlea + otitis media
Tumor on 8th cranial nerve + closed external
auditory meatus
Noised-induced hearing loss + wax build-up
Basically, any conductive less + nerve damage
Mixed Loss: How much? How
Can it be Fixed?

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The loss of dB (how
much you can hear)
depends on how much
sensorineural loss
combined with the
conductive loss
The conductive loss
can most likely be fixed;
however, the
sensorineural loss
cannot.