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What
Is Hearing Loss?
Each day in our offices,
we see patients with hearing capability that runs anywhere from hearing well to
not hearing at all. There are four terms used to categorize the degree of
hearing loss an individual can experience: mild, moderate, severe and profound.
Most hearing losses are in the mild to moderate category.
There are two predominant types of hearing loss. One is conductive - a hearing
loss that prevents sound from being conducted through the ear canal to the inner
ear. This can be caused by physical problems in the external or middle ear,
including ear wax blockage, debris in the ear, infection and swelling, eardrum
perforation, or abnormalities with the bones in the middle ear. Some conductive
hearing loss is reversible if the physical condition is corrected.
The second type of hearing loss is known as sensorineural: this occurs in the
area beyond the middle ear (the inner ear), including the auditory nerve. For
example, this is where damage from excessive exposure to loud sound takes its
toll, and this damage is irreversible.
A mixed hearing loss is when a combination of the two predominant types of
hearing loss is present.
A conductive hearing loss usually results in a deficiency in the ability to hear
low frequency sounds. In speech, sounds such as "o" and "u", which provide most
the "volume" of speech are affected the most. This results in lower loudness of
incoming speech sounds, but sometimes affecting their clarity.
A sensorineural hearing loss oftens affects the ability to hear higher-pitched
speech sounds. "S", "f", "sh", and "t" are examples of those sounds which are
missed by an individual with a sensorineural hearing loss. Most people with this
type of loss will often say they can hear that something is being said, but
cannot understand it.
How
is Hearing Loss Diagnosed?
There are two
standard, non-invasive tests -- puretone air conduction and puretone bone
conduction - that are performed to determine whether or not an individual has a
hearing loss of any consequence. These procedures test an individual's ability
to hear the range of frequencies that make up human speech.
Puretone air conduction is done through the use of headphones, worn by the
patient, through which the patient hears a series of specific tones. The purpose
of this test is to find the softest level of sound the patient is able to hear
as it passes through the outer ear, middle ear and inner ear.
Puretone bone conduction also uses tone, with the tones delivered via a headband
similar to that in air conduction, except instead of earphones, a device
resembling a headband is placed just behind the individual's ear. The tones
generated are heard not through the outer ear, but as vibrations picked up by
the inner ear, giving the audiologist a clearer picture of where the patient's
hearing loss is occuring .
If a hearing loss is detected, there are further tests we may do to diagnose or
rule out other factors that might be contributing to the individual's hearing
loss.
How
Can I Tell If I Have A Hearing Loss?
Many of us have gotten used to wearing eyeglasses every day: in fact, we know
instantly when we've forgotten to put them on - suddenly we're disoriented and
frustrated at not being able to see clearly.
As our ability to hear diminishes over time (and it does for most people as they
age), the change is very gradual - often going completely unnoticed. However,
age is not the only factor that plays a part in hearing loss: loud music, power
equipment, certain medications, genetic factors, and general over-exposure to
excessive noise of any kind can bring on hearing loss in people of any age.
Think you might have a hearing loss? It's possible, especially if one or more of
the following happens to you on a regular basis:
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frequently asking people to repeat what they've
said; |
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sitting closer to the front for concerts,
lectures, seminars, and religious services; |
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someone mentions that your TV or radio is very
loud; |
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people seem to be "yelling" at you when they
talk to you. |
The early stage of
hearing loss is present when an individual can hardly (or not even) hear the
following sounds:
Birds chirping
Crickets or peepers
Wall clock ticking
Light rainfall outside an open window
Fireplace crackling
Someone whispering five feet away in a quiet room
A hearing loss is worsening when an individual has difficulty hearing or
understanding sounds such as:
Wind chimes outside an open window
Doorbell or telephone ringing (if not in the same room)
Unamplified presentations, lectures, religious services, etc. in large rooms
Car horns and/or sirens when car windows are closed
People calling to them from another room
Cat meowing
Approaching footsteps
The personal safety of an individual and those around them is jeopardized when
the following sounds are difficult to hear or understand, especially at short
distances:
Radio or television
Smoke or fire alarms
Doorbell and/or telephone ringing
People standing nearby, but facing away from you while speaking
Dogs barking (especially in warning)
Ambulance or police sirens while driving
For those with increasing hearing loss, day to day activities can become
unfulfilling, unpleasant and even dangerous - the importance of sound in our
everyday lives cannot be understated.
How
Do Hearing Aids Correct A Hearing Loss?
The ear is a complex
system of bones, nerves, and tissue that allows us to understand sound. The
sound we hear is transmitted via the auditory nerve to the brain. If our hearing
diminishes, hearing instruments may help to amplify those sounds coming into our
ear.
Each hearing instrument has a miniature microphone that "hears" sounds the user
may no longer be able to hear. The sound is amplified and sent into the user's
ear canal. Filters and processors built into the hearing aid electronically
modify and enhance the incoming sound to correct the user's particular hearing
loss (see the section titled "What
is Hearing Loss?").
Hearing instrument technology is continually improving: the very sophisticated
electronic circuits and computer chips currently being used in many hearing aids
produce high-quality sound reproduction, and many are computer-programmable to
fine-tune the incoming sound to compensate for the specific hearing needs of the
user.
One very important factor to remember: Patience is the key when wearing a
hearing aid for the first time. When you begin using a hearing aid, you will
hear everything around you. While the hearing aid can be programmed to
compensate for your particular hearing deficiency, it cannot filter out specific
sounds - that is the job of your brain.
The new digital hearing aids can decrease the non-speech sounds you hear, making
speech sound louder. However, when there are many people speaking at the same
time, it may be difficult to differentiate one voice from another. Hearing aids
with directional microphones make it easier for the wearer to single out a
particular individual on those occasions when many people are present.
As an individual's hearing diminishes, the brain "forgets" how to filter out
background noises because it can no longer detect them. When you begin wearing a
hearing aid, your brain needs to re-learn how to filter out what you don't want
to hear, and to concentrate on what you do want to hear. For example, it will
take a little time to be able to have a conversation with someone next to you
while standing in a noisy area. Once your brain re-adjusts to having a
full-range of sound available, you will find your hearing aid to be a wonderful
investment, as it will add a great deal to your enjoyment of the world around
you.
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