Everyday Noises Can Be Harmful to Hearing

It is generally well known that noise levels at rock concerts can cause permanent hearing damage in humans. But there are many other noises around in everyday life that can be just as harmful as the loudest rock music.

This is the conclusion of research conducted by Dr. Kenneth O. Jones, assistant professor of communicative habilitation at Brigham Young University.

Dr. Jones has run tests on teenagers with noise-induced hearing losses comparable to those of men who have spent a lifetime working in noisy factories. Rock concerts and stereos turned up full blast account for some of these teenage hearing losses but they are not the only villains. For instance, a snowmobile produces a sound pressure level averaging 108 decibels on the A measuring scale (dBA), while a rock concert averages 102 dBA, Dr. Jones stated. The U.S. Occupation Safety and Health Act of 1970 specifies that no one should be exposed to 108 dBA for more than 45 minutes or 102 dBA for more than 90 minutes.

“If you attend one rock dance for a couple of hours or ride a snowmobile for an hour, you can lose a little bit of your hearing permanently,” Professor Jones warned.

He pointed out that strict adherence to the Safety and Health Act is supposed to protect 50 percent of the population. This means that many people sustain a certain amount of permanent hearing loss when exposed to noises below the specified safe limits.

The general public needs to become aware that many sounds encountered in daily life can cause permanent hearing damage. For example, a table saw will average 100 dBA; a power lawn mower, 95; and a kitchen blender, 91. Safe exposures for each of these levels, according to federal standards, are two, four, and eight hours respectively.

“Basketball games at BYU have been measured as high as 105 dBA,” Dr. Jones said. “The level doesn’t remain constant at 105 dBA, but if it did for more than an hour, we would be violating the Safety and Health Act.”

Dr. Jones and his assistants have found hearing losses caused by noises from gunfire, dentist drills, helicopters, oil well derricks, television and stereo sets, and power tools, among other things.

Unfortunately, noise-induced hearing losses are not easily corrected by hearing aids, and once sustained, they remain for life, Dr. Jones explained. The ears become insensitive to the higher hearing range frequencies, making it difficult to distinguish the soft “th,” “s” and “wh” sounds.

Paradoxically, people with noise-induced hearing losses are actually bothered by noise. Those who insist on listening to loud music will enjoy it less and less as time goes by.

Since noise-induced hearing losses occur slowly, they are difficult to detect at first. But one sign of possible damage is a ringing in the ears after being exposed to harsh, sharp, or loud sounds.

Since noise-induced hearing losses are permanent and are hard to correct with hearing aids, the key to the problem is to prevent the losses in the first place. This means eliminating the noise if possible, and if that can’t be done, the exposed person should be equipped with protective devices, such as specially made ear plugs, ear cups, or sound helmets.

As for eliminating or reducing the noise, much could be done by manufacturers if they would equip their machinery with proper mufflers or other sound-deadening devices, Dr. Jones says. “These things can be done and they will be done as the public becomes aware of what is happening in the world of noise pollution and demands that something be done.”