|
Types/Degrees of Hearing Loss |
| |
|
|
In this section
we will cover the different types of hearing loss and the degree of
hearing loss evaluated by an audiogram (hearing test). |
| |
|
Hearing loss can be attributed to a number of
reasons. For some of us, the cause of hearing loss could be the
result of earwax buildup. For others, it could be damage to the
cochlea where your electrical signals are not being transmitted
efficiently.
Some additional causes of hearing loss include:
Aging, genetic, exposure to loud sounds, ruptured eardrum, ear
infection, or abnormal bone growth of the outer or middle ear.
|
| |
|
| |
|
|
Types of Hearing Loss |
| |
|
Hearing loss can be categorized by where or what part of the
auditory system is damaged. There are
three basic
types of hearing loss:
conductive hearing loss,
sensorineural hearing
loss and
mixed hearing loss.
Below is a description of each type of hearing loss, with the
potential treatment and possible causes. |
| |
|
- Conductive Loss
-
Hearing loss when there is a problem conducting sound waves
through the outer ear, eardrum, or middle ear with
indication of normal inner ear activity. This type of
hearing loss may occur in conjunction with sensorineural
loss or alone. In most situations, conductive hearing loss
can be medically or surgically corrected. Possible
Causes: Wax in ear canal, perforation in the
eardrum, or fluid in middle ear.
-
Sensorineural Loss
-
Type
of hearing loss that occurs when there is a problem in the
inner ear or hearing nerve pathway between the inner ear and
brain. Most sensory hearing loss is due to poor hair
cell function. The preferred treatment for
sensorineural hearing loss is hearing aids. Possible
Causes: Prolonged exposure to very loud noises,
aging, infection, or a genetic disorder.
- Mixed Hearing
Loss
- Refers
to a
conductive and a sensorineural hearing loss occurring at the
same time. As referenced above, the conductive
component may be treated, the sensorineural component is
permanent. Possible Causes: Please see above.
|
|
Terms that describe
the side or sides on which the hearing loss occurs: |
| |
|
- Unilteral -
there is a hearing loss in one ear
- Bilateral -
there is a hearing loss in both ears
|
| |
|
|
Degree of Hearing Loss |
| |
|
The degree of hearing loss is defined as the severity of the hearing
loss measured by hearing tests. When you get an audiological
evaluation (hearing test), this is just one of the parts that your
hearing healthcare specialist will show you after completing the
test. The audiogram is very important to determine the degree
of hearing loss, in order to seek appropriate treatment. On
the chart below, the numbers illustrate a measurement of what levels
of frequencies can and cannot be heard, what degree of hearing loss
that it refers to, and what your ability is to understand speech. |
| |
|
| |
Hearing Threshold
in decibels (dB) |
Degree of
Hearing Loss |
|
| |
0-20 dB |
Normal |
|
| |
20-40 dB |
Mild |
|
| |
40-60 dB |
Moderate |
|
| |
60-80 dB |
Severe |
|
| |
80+ dB |
Profound |
|
| |
- Mild Hearing Loss
- A
person
with a mild hearing loss may hear some speech sounds but
soft sounds are hard to hear. This type of loss can
typically be managed in a quiet environment.
-
Moderate
Hearing Loss
- A
person
with a moderate hearing loss may hear almost no speech when
another person is talking at a normal level.
Background noise provides a challenging listening experience
when understanding conversational speech and often times
patients will need to increase the volume levels of their
radio, TV, IPod, etc.
-
Severe
Hearing Loss
- A
person
with severe hearing loss will hear no speech of a person
talking at a normal level and only some loud sounds.
You might also have difficulty with amplified speech.
-
Profound
Hearing Loss
- A
person
with a profound hearing loss will not hear any speech and
only very loud sounds.
|
| |
|
Audiogram with Speech Sounds |
| |
|
The hearing
loss on an audiogram explains the severity of ones’ hearing
inability. The diagram below shows what the sounds are that we
usually hear everyday and at what decibel (left hand side) the sound
is heard. Normal hearing is from 0 - 20 decibels (dB) defined
by the area shaded in grey. As you can see on the chart, those
without hearing loss would be able to hear all sounds on the chart. |
| |
|
 |
| |
|
|
If hearing healthcare professionals use terms that you don't
understand, please ask questions. |
| |
| |
|
Related Links to Understanding
Hearing |
|
|
|
|
