Here's to better hearing
By Col. Robert A. Gardner
43rd Medical Group Chief of Medical Staff
Have you ever been sitting at a traffic stop when suddenly
a deep vibrating noise rattles the steering wheel and even drowns your ability
to think? Five car-lengths behind you is a vehicle literally rattling the
pavement with the "boom boom boom" of its car stereo.
Yes, it's hard to imagine a time when the planet was quiet - a time when
the call of animals, the rustle of the wind or the chirping of crickets
was about as noisy as it got. Today, however, the world is filled with engineered
noise. From modern electronic gadgetry to deafening crowds at sporting events,
noise explodes into our lives every moment of the day.
According to the National Institute on Deafness and Other Communication Disorders, some 30 million Americans are at risk for noise-induced hearing loss. And this rising crisis is occurring much sooner than 30 years ago. Sadly the younger generation has become its newest victims.
American homes, recreational settings and workplaces are riddled with excessive noise. More than 10 million people have permanently damaged hearing, it is such a serious matter that many states and communities have passed stringent anti-noise laws. For instance, the Oklahoma Senate passed a bill in 2000 that fines individuals from $100 to $500 and 30 nights in jail who operate motorcycles, cars or play amplified audio systems within ordinary hearing distance of 150 feet.
What is noise?
One person's noise is another person's concert. Noise expert, K.D. Kryter,
defines noise as "acoustic signals, which can negatively affect the
physiological or psychological well-being of an individual." In essence,
chronic loud noise can affect your health and safety.
How loud is too loud?
Too loud is when you have trouble hearing over the telephone; normal conversation
is muffled, especially the speech of children and female voices; you ask
people to repeat things; or there may be a vague feeling of pressure or
fullness in the ears or you just can't shake that high- pitched ringing
or buzzing in your ear.
One reason people don't notice the danger of noise is that excess exposure
to noise cause few symptoms.
Hearing loss is gradual and rarely painful. There are tiny delicate hearing
cells, called "hair-cells" line the inner ear like a piano keyboard
covered with water. Attached to one end of the cells are nerve fibers that
carry the sound to the brain centers.
Sound can cause a gentle ripple across the hearing cells or a raging tidal
wave depending on how loud or persistent the sound. If too loud, "hair-cells"
are destroyed. Unfortunately, once destroyed those "piano-keys"
or hearing cells are lost forever.
What is a "decibel?"
Decibel levels
This noise chart gives you an idea of how much noise things make:
Painful:
150 db = rock music peak
140 db = firearms, air raid siren, jet engine
130 db = jackhammer
120 db = jet plane take-off, amplified car stereo
Extremely Loud:
110 db = rock music, model airplane, head-sets
106 db = bass drum roll
100 db = snowmobile, chainsaw
90 db = lawnmower, truck traffic, subway train
Very Loud:
80 db = alarm clock, busy street
70 db = vacuum cleaner
60 db = conversation, dishwasher
Moderate:
50 db = hard rainfall
40 db = quiet room
Faint:
30 db = whisper, quiet library
db = decibel
A decibel is a way of expressing relative differences in sounds. It is measured on a scale from zero to 140. Sounds louder than 85 decibels can damage your ears.
I'm losing a few "hair-cells," so what?
Noise not only affects hearing, but it can also affect other body parts
and systems. For example, noise can:
· Increase blood pressure
· Adversely affect heart rhythms
· Increase breathing
· Disturb digestion and cause ulcers
· Negatively affect developing fetuses, contribute to premature births
· Cause insomnia, even after the noise stops
· Intensify the effects of drugs, alcohol and carbon monoxide
· Stimulate aging
· Increase fatigue, irritability, anger ("road-rage") and
frustration
· Reduce efficiency in performing daily tasks or lower the attention
span
How can I protect myself from harmful noise?
The key is prevention. Eliminate unwanted noise when possible or keep it
as low as possible. Remember "increased decibels = decreased hearing."
Here are some tips:
· Limit exposure time. Don't sit next to the speakers at concerts,
discos or retirement ceremonies (even if the seats are free or cheap).
· Pump down the volume. Portable radios, amplified car stereos, head-sets,
whatever; if your friend can hear your music or feel your bass speakers
when standing 50 feet away, the volume is definitely too high.
· Wear hearing protection. Consider Active Noise Reduction headsets
at work, on airplanes, while mowing the lawn or using power tools.
· They contain a microphone in each earpiece that listens to incoming
low-frequency noise and sends the information to a controller for analysis.
The device then creates an inverse or (anti-noise) acoustic output signal
that cancels out the noise and eliminates it. They sell for around $300.
· Be a responsible consumer. Check out the noise rating on tools,
appliances, children's toys and electronic audio equipment.
· Have your hearing tested. by an audiologist annually or at least
every few years.
· Be noise smart. Know where to get information. Here are some links:
· www.asha.org
· www.lhh.org/noise
· www.nidcd.nih.gov
· www.hearnet.com
· www.nonoise.org
· www.cdc.gov/niosh/topics/noise/
· www.safe-at-work.com
· www.kidshealth.org
· www.lighthousewoods.com/noisy_vehicles.html