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Hearing is our most important sense for
interpersonal communication, much more so than the senses
of vision, touch, and smell. The sense of hearing is dependent
on the ear and brain. Damage to either is capable of causing
anywhere from a mild to severe reduction in the ability
to communicate with others as well as awareness of the sounds
of the world around us.
The ear is a tiny,
but magnificent and complicated organ. It is capable of
detecting a force that moves the eardrum approximately
one one-hundred-millionth of an inch and yet is able to
tolerate a sound one hundred trillion times more powerful.
The ear can detect up to 280 changes in sound level and
distinguish about 1400 discrete pitch changes. This total
of about 400,000 loudness/pitch discriminations may stimulate
as many as 618,000 cells of the auditory complex which
make possible our very complicated system of communication
through speech.
Damage to the
ear, the nerve of hearing, and the auditory cortex can
occur at any time in life. Damage to different parts
of the auditory system often result in specific symptoms
that the audiologist is trained to evaluate. Hearing
tests are not performed just to determine how well you
hear, but to determine:
- What part of the auditory
system is damaged
- The extent of the damage
- The course of treatment and/or
rehabilitation
|
Ear Chart |
1.Outer
or External Ear |
2.Middle Ear |
3.Inner Ear |
4. Semi-circular canals
(labyrinth) |
5.Auditory nerve |
6.Cochlea |
7.Eustachian tube |
8.Incus |
9.Stapes |
10.Oval window |
11.Eardrum (tympanic
membrane |
12.Malleus |
13.Ear lobe |
14.External Auditroy
Canal |
15.Pinna |
16.Bone |
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| Damage to the Auditory System is Classified
in Different Ways |
| First,
the auditory system is subdivided into the outer ear,
middle ear, inner ear (cochlea), eighth nerve, brainstem,
and auditory cortex. Hearing loss resulting from disorders
of the outer and middle ear are called conductive hearing
loss and can often be treated by an Ear Nose and Throat
specialist with medicine or surgery. Hearing loss resulting
from disorders of the cochlea are called sensory. These
disorders are usually not treatable by medicine or surgery.
Hearing loss resulting from disorders of the eighth nerve,
brainstem, and auditory cortex are called neural disorders
and may or may not be treatable by medicine or surgery.
The audiologist is trained to evaluate all of these types
of disorders and to treat (habilitate or rehabilitate)
hearing loss caused by the these disorders in the event
that they cannot be helped by medicine or surgery. |
Another
way hearing loss is categorized is by the degree of hearing
loss and the effect it has on communication. The degree
of hearing loss is measured and recorded on an audiogram
in decibels
(dB) at different frequencies (pitches).
|
Average
Threshold
Level at
500-2000 Hz |
Description
|
What
can be heard without amplification |
|
0-15 dB |
Normal
range |
All speech sounds |
16-25 dB |
Slight hearing loss |
Vowel sounds heard clearly, may miss
unvoiced consonant sounds |
| 26-40 dB |
Mild hearing loss |
Hears only some of speech sounds usually
the more loudly voiced sounds |
41-65 dB |
Moderate hearing loss |
Misses most speech sounds at normal
conversational level |
66-95 dB |
Severe hearing loss |
Hears no speech sound of normal conversations |
| 96+ dB |
Profound hearing loss |
Hears no speech or other sounds |
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| 100
West Fourth St., Suite 320
Cookeville, TN 38501
(931) 526-8863 |
2069 New Smithville Hwy
McMinnville, TN 37110
(931) 473-3833 |
1700
West Ave. North
Crossville, TN 38555
(931) 456-2952 |
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