What are the sounds of summer for you? Is it the crash of surf on the beach? Is it the nighttime call of a screech owl in the woods near your sleep-away camp? Is it the crack of a baseball bat hitting a ball? Or is it the jingle of the bells on the ice-cream truck as it comes down your street?

Whatever the time of year, the world around us is filled with sounds, both loud and quiet. Your ears are designed to gather and interpret an amazing range of the sounds that travel through the air. But to keep them functioning at their best, you sometimes need to protect your ears from sounds that can cause damage.

Experts at the National Institute on Deafness and Other Communication Disorders (NIDCD) are concerned that our ears are exposed to way too much noise. NIDCD, which is part of the National Institutes of Health in Bethesda, has joined other health and safety organizations in creating Wise Ears, a public awareness campaign to teach families more about hearing.

When someone is exposed to sounds that are too loud, sensitive parts of the inner ear can be damaged. Deep inside the ear are ultra-delicate hair cells, whose job is to deliver messages to the brain. These fragile cells can be damaged by either a burst of intense noise, such as a firecracker bang, or by continuous exposure to sounds such as rushing subways or whining saws in a woodworking shop. The result can be a condition called noise-induced hearing loss.

Someone with noise-induced hearing loss may experience sound as distorted or muffled and may have difficulty understanding speech.

It can be hard to avoid loud noise--but you should whenever you can. Did you know that:

* If you are standing next to a person wearing a personal radio with earphones and you can hear the lyrics to the song, that person is damaging his or her hearing?

* If you are doing lawn work for the summer, using a power mower hour after hour without wearing ear protection, you are damaging your hearing?

In both these examples, it is easy to avoid damage. The person playing the loud radio needs to turn it down! And the lawn worker needs to wear earplugs or special ear protectors.

The National Center for Health Statistics reports Americans today are losing their hearing at younger ages than in previous generations.Ten million people in this country have already suffered irreversible damage from noise and 30 million are exposed to dangerous levels of noise each day. NIDCD Director James F. Battey Jr. says: "It is alarming that Americans are losing their hearing at a younger age. The greatest increase occurs for people 45 to 64 years old. This is almost 20 years younger than we would expect. Noise exposure appears to be the culprit."

Noise is measured in units called decibels. City traffic noise is 80 decibels. Normal speech is 60 decibels. A whisper is 30. A healthy ear can pick up sounds starting at zero decibels. Damage can begin with exposure to noises over 75 decibels, according to the NIDCD. Here are some common noises that can damage hearing:

* Chain saw (110 decibels)

* Pneumatic drill (119 decibels)

* Ambulance siren (120 decibels)

* Jet engine at takeoff (140 decibels)

* Rock concert (140 decibels).

As you listen to the sounds of summer, try to avoid getting too close to very loud noises. Turn down the volume when you're listening to music. Enjoy the quiet! Your ears will thank you by staying sensitive to sound for years to come.

Tips for Parents

How often do you have to ask your kids to turn down the music? (And how often did your parents ask you to turn yours down when you were growing up?) To help convince your kids that they really may harm their hearing, it can help to have up-to-date materials to share with them. For information about hearing loss, including the Wise Ears coalition, contact the NIDCD Information Clearinghouse in Bethesda at 301-496-7243 or check the group's Web site, www.nih.gov/nidcd/health/wise.

Headline: For You to Do

Naturalists--people who study the world of nature--often maintain notebooks in which they write down their observations about animals, plants, birds, insects and the weather. For a few days, become a sound naturalist. Using a small notebook, spend time really listening to the sounds in the world around you, both indoors and outside. Sit very still and pay attention to your environment. What seemed like silence at first may actually be filled with birds chirping, distant voices, the whir of a fan or the shrill ring of a telephone next door. Write down notes about whatever you hear. Rate the sounds as quiet, normal, loud or too loud. After a day or two of note-taking, analyze your findings. Are you often exposed to loud noise? Normal noise? Do you think you spend too much time exposing your ears to sound that is too loud? How do you think you can change your environment to protect your ears best?