loss is best described by varying degrees, not percentages. Hearing
loss may be "mild", "moderate", "moderately-severe",
"severe" or "profound" and may vary across pitches.
degree of loss is determined by a simple hearing test where the
individual is presented with a variety of tones at different pitches
and amount of volume. The
volume or intensity of sounds that one hears is measured in decibels
(dB). The softest whisper is 0 dB while a jet engine is as
loud as 125 dB. The
softest sounds one can hear are called thresholds.
Normal hearing thresholds for adults range form 0 to 25dB.
Is Hearing Loss?
permanent hearing loss is due to damage to hair cells in the cochlea
located in the inner ear. Picture someone playing a piano
with an entire section of keys not working because the strings inside
the piano are missing. They are playing a song you should
know but you don't recognize it because large segments of the music
are missing. Well, that is how your brain is trying to hear
if you are missing parts of the speech frequencies. Instead
of damaged piano strings, large segments of hair cells are damaged.
Just like the music, words can become unintelligible.
Causes Hearing Loss?
of hearing loss are many and the impact of each on hearing is varied.
Sometimes the cause is readily apparent, such as a wax build-up
in the external ear canal or an ear infection. At other times,
the cause of the hearing loss is physiological or mechanical in
causes of hearing loss are:
- Excessive noise (i.e.,
construction, loud machinery, rock music, repeated gun shot, etc.)
- Aging (also called
- Illness (such
as tuberculosis, Lyme disease, Scarlet fever, meningitis, etc.)
- Injury to
- Birth defects
- Heart attack
to drugs, medications, or treatment (i.e., antibiotics, chemotherapy,
of the bones of the middle ear (arthritis)
of Hearing Loss
There are many
kinds of hearing loss. Each one has its own unique causes
type of hearing loss occurs when there is a problem
with the way sound is conducted, or transmitted, to
the inner ear where the cochlea is located. The problem
may lie in the outer ear (pinna, auditory canal, or
ear drum) or the middle ear (the ossicles or Eustachian
tubes). The inner ear remains unaffected by this type
of hearing loss.
causes of conductive hearing loss include outer or middle
ear infections, complete blockage of the auditory canal
by earwax buildup or introduction of a foreign object,
a ruptured ear drum, deterioration or arthritic buildup
of the ossicles, blockage of the Eustachian tubes, or
absence of the outer or middle ear structures.
hearing losses may be temporary or permanent, depending
on the source of the problem. Medical management
in the form of antibiotics can be used in some cases
to treat infections, and there are many excellent ear
wash products that can effectively remove earwax buildup.
Also, surgical procedures can be used to replace
damaged or malfunctioning ossicles in severe cases.
Finally, amplification may be a recommended treatment
option in more long-standing or permanent cases.
with conductive hearing loss may report that sounds
are muffled or quiet. Generally, when sounds are made
louder, hearing improves in such individuals.
type of hearing loss occurs when there is damage to
or an abnormality in the sensory hair cell receptors
in the hearing system, specifically in the cochlea of
the inner ear. Such abnormalities prevent sounds
from being transmitted to the brain in a normal fashion,
resulting in hearing loss.
hair cells may have been abnormal from birth or damaged
as a result of infection, drugs, trauma, or over-exposure
to extremely loud sounds. People working in and
around loud machinery are particularly susceptible to
this type of hearing loss. It is also becoming more
common in younger people who attend loud concerts or
listen to music using headphones with the sound set
too high. The condition can also be a result of
the aging process, a kind of hearing loss known as presbycusis
with sensorineuronal hearing loss may report muffled
speech, ringing in the ears (tinnitus), difficulty hearing
when there is loud background noise, or complaints that
other people do not speak clearly.
aids are generally recommended as a treatment option
in such cases.
its name implies, this condition occurs when a person
has a sensorineural hearing loss in combination with
a conductive hearing loss. This means there is
a problem in the inner ear as well as in the outer or
hearing loss is often treated with a combination of
medical management and the fitting of proper hearing
hearing loss occurs when the auditory nerve that carries
electrical impulses from the cochlea to the brain is
missing, damaged, or abnormal. It is difficult
to determine the exact location of neuronal hearing
loss. Some causes of neuronal hearing loss include
genetics, acoustic tumors, in-utero exposure
to certain infections, severe jaundice in infancy, and
low birth weight associated with premature birth.
with this type of hearing loss often have difficulty
understanding speech, even when it is loud enough, as
well as difficulties with background noise.
in the form of proper hearing aids may be recommended
in some cases depending on the severity of damage to
the auditory nerve.