Of the 28 million Americans who have some degree of hearing loss, about one-third can attribute their hearing loss, at least in part, to loud noise.

We hear when the ear converts sound waves into electrical signals sent to the brain and interpreted as sound. The ear has three main parts: the outer, middle, and inner ear( see illustration). Sound waves enter through the outer ear and reach the middle ear where they cause the eardrum to vibrate. The vibrations are transmitted through three tiny bones known as the hammer, anvil, and stirrup. The eardrum and bones amplify the sonic vibrations and carry them to the inner ear. The stirrup transmits the amplified vibrations through the oval window and into the fluid that fills the inner ear. The vibrations move through fluid in the snail-shaped hearing part of the inner ear (cochlea) that contains the hair cells. The fluid in the cochlea moves the top portion of the hair cells, called the hair bundle, which initiates the changes that lead to the production of nerve impulses.

These nerve impulses are carried to the brain, where they are interpreted as sound. Sounds move the hair bundles in different ways allowing the brain to distinguish one sound from another, such as vowels from consonants.

Noise Induced Hearing loss (NIHL) can be caused by a one-time exposure to loud sound as well as by repeated exposure to sounds at various loudness levels over an extended period of time. Loudness is measured in units called decibels. Normal conversation is approximately 60 decibels, a refrigerator, 40 decibels, city traffic noise can be 80 decibels (Db). Loud noises that cause NIHL are motorcycles, firecrackers, and firearms, all emitting sounds from 120 to 140 Db. Sounds of less than 80Db, even after long exposure, are unlikely to cause hearing loss. Your iPod or other personal audio device set at 60 percent of its top value is about 80 Db.

Exposure to harmful sounds causes damage to the sensitive hair cells of the inner ear as well as the hearing nerve. These structures can be injured by two kinds of noise: loud impulse noise, such as an explosion, or loud continuous noise, such as that generated in a woodworking shop.

Symptoms - Symptoms of NIHL increase gradually over a period of continuous exposure. Sounds may become distorted or muffled, and it may be difficult for the person to understand speech. The individual may not be aware of the loss, but it can be detected with a hearing test.

NIHL is preventable - Know that noise above 90 decibels noises can cause damage. (about 7 out of a 10 on your iPod setting).

- Wear earplugs or other hearing protective devices when involved in a loud activity (special earplugs and earmuffs are available at hardware stores and sporting good stores).

- Be alert to hazardous noise in the environment.

- Protect children who are too young to protect themselves.

- Make family, friends, and colleagues aware of the hazards of noise.

- Have a medical examination by an otolaryngologist or physician who specializes in diseases of the ears, nose, throat, head, and neck, and a hearing test by an audiologist, a health professional trained to identify and measure hearing loss and to rehabilitate persons with hearing impairments.

Elder hearing Loss

Elder hearing loss is one of the most common conditions affecting older adults. One in three people older than 60 and half of those older than 85 have hearing loss. Hearing problems can make it hard to understand and follow a doctor's advice, to respond to warnings, and to hear doorbells and alarms. They can also make it hard to enjoy talking with friends and family. All of this can be frustrating, embarrassing, and even dangerous.

Some people lose their hearing slowly as they age, a condition known as presbycusis (prez-buh-KYOO-sis). Doctors do not know why it happens, but it seems to run in families. Sometimes loud noise can cause a ringing, hissing, or roaring sound in the ears, called tinnitus (tin-NY-tus).

Tinnitus is a symptom associated with many forms of hearing loss. It can also be a symptom of other health problems. According to estimates by the American Tinnitus Association, at least 12 million Americans have tinnitusand at least 1 million experience it so severely that it interferes with their daily activities. People with severe cases of tinnitus may find it difficult to hear, work, or even sleep.

Causes of Tinnitus - Doctors and scientists have discovered that people with different kinds of hearing loss also have tinnitus.

Too much exposure to loud noise can cause noise-induced hearing loss and tinnitus.

More than 200 medicines can cause tinnitus. If you have tinnitus and you take medicine, ask your doctor or pharmacist whether your medicine could be involved.

Allergies, tumors, and problems in the heart and blood vessels, jaws, and neck can cause tinnitus.

Remedy -See your doctor who can try to determine what is causing your tinnitus to see if it's related to blood pressure, kidney function, diet, or allergies or, perhaps any medicine you are taking. Although there is no cure for tinnitus, scientists and doctors have discovered several treatments that may give you some relief such as:

Try hearing aids, relaxing, or possibly maskers, which are small electronic devices that use white noise. They don't make tinnitus go away, but they make the ringing or roaring seem softer like listening to static at a low volume on the radio. Avoid anything that can make your tinnitus worse including smoking, alcohol, and loud noise. If you are regularly exposed to loud noise at home or at work, wear ear plugs or special earmuffs to protect your hearing and keep your tinnitus from getting worse.

By Steve Bobo
http://www2.townonline.com/cohasset/opinion/view.bg?articleid=427727