The Monday after a Bruce Springsteen concert last year, the hearing-speech clinic at Washington Hospital Center treated five people for temporary hearing loss. Clinic director David Resnick's daughter was among them.
"And that was just this clinic," Resnick says. "I don't know how many people were seen by other clinics in the area."
Rock concerts are just one of the modern experiences that are linked to increasing reports of noise-related health problems.
Excessive exposure to noise is, according to audiologists, the primary cause of hearing disorders. Studies have also linked noise to high blood pressure and other stress-related disorders that can lead to heart disease, low infant birth weights, insomnia, anxiety, headaches, colitis (inflammation of the large intestine) and ulcers.
One in 10 people in the United States has some degree of hearing loss, according to Jill Lipoti, formerly with the federally funded Noise Technical Assistance Center at Rutgers University.
Resnick says his clinic is seeing increasing numbers of clients with noise-related problems. So does audiologist Richard Israel of Silver Spring. "No doubt about it," Israel says, adding that he has noticed the greatest increase among young people, particularly those with histories of noise exposure.
Job-related hearing complaints are on the increase and many are winding up in court. Resnick says Washington Hospital Center is seeing more and more people referred by the Department of Labor and attorneys for examinations to back up claims. Some cases have involved printing presses, construction sites and Metro tunnel blasting, according to a hospital spokeswoman.
It's not as easy to prove that long-term exposure to everyday urban noise causes problems. But according to one study done years ago, Resnick says, hearing deterioration that people in the United States accept as a part of the aging process may actually be a result of environment.
In 1960, Columbia Medical School studied the Maabaans, a remote Sudanese tribe living in a jungle environment where the loudest noise was the occasional singing and dancing of the tribe's young people. The hearing of the oldest person, an 80-year-old, was found to be as sharp as that of the average 30-year-old American.
The Maabaan study can't be considered proof that environmental noise causes hearing loss, because there was no control group of Maabaans living in a noisy environment, but, says Resnick, "It makes you think."
"Noise loud enough to cause hearing loss is virtually everywhere today," says the Environmental Protection Agency's 1978 booklet "Noise: A Health Problem." "Our jobs, our entertainment and recreation, and our neighborhoods and homes are filled with potentially harmful levels of noise."
EPA researchers have said the danger level for hearing loss begins when daily noise averages about 70 decibels. A noisy restaurant can be 70 decibels; a vacuum cleaner puts out 75 decibels. The general noise level in urban neighborhoods can range from the high 60s to the high 80s, depending on how close they are to airports, construction sites and major highways. And harmful noises also exist in the city: a portable jackhammer at 10 feet is about 90 decibels; a jet flying at 1,000 feet directly overhead is 103 decibels.
Excessive noise damages the tiny hair cells in the ears, which convert wavelike motions in the fluid-filled chochlea -- motions created by sound waves -- into the neural impulses that the brain interprets as sound. Resnick compares the damage to a jump rope that begins to fray after heavy use. Each exposure to sound over 85 decibels does a small amount of damage to these hair cells. And the effect is cumulative.
Other health effects of noise have also been documented.
University of Miami scientists looked at rhesus monkeys, whose cardiovascular system is similar to that of humans. For nine months the monkeys were exposed to noise that an industrial worker might experience both on and off the job. Over time their blood pressure jumped by about 30 percent, an increase that remained long after the noise ceased.
High blood pressure can lead to heart disease. So can stress. And according to the EPA, noise is definitely a cause of stress. "Our bodies make automatic responses to sudden or loud sounds . . . Blood pressure rises, heart rate and breathing speed up, muscles tense, hormones are released into the bloodstream, and perspiration appears. These changes even occur during sleep . . . Even when we think we have become accustomed to noise, biological changes still take place."
Researchers also say noise may be associated with ulcers, asthma, headaches, colitis and even respiratory ailments. Some psychological studies indicate it may make us less sociable (perhaps because it's harder to communicate) and more aggressive and that it might aggravate existing mental problems.
A fetus is responsive to sounds in the mother's environment, EPA researchers note, and also responds to stress-induced changes in the mother's body. That response is thought to be a hazard to early fetal development, although there has been little specific research done. One study in Japan of more than 1,000 births showed a higher percentage of low-weight babies in noisy areas.
Noise also erodes a person's sense of well-being. It can cause anxiety, irritation, anger, difficulty sleeping and feelings of being out of control, experts say.
Noise tends not to get the public attention that some other environmental health hazards do. For one thing, it can't be seen. It's difficult to separate noise from other causes of stress. And noise-related troubles appear slowly.
The EPA has conducted studies and produced several publications on noise and health. But in 1982, the Reagan administration decided to dismantle the EPA's noise control office. Funds have been phased out over two years. The last money ran out last month with the closing of the Rutgers Technical Assistance Center, originally one of 10 regional centers across the country set up to answer noise questions and help localities develop control strategies.
Dr. Luther L. Terry, former U.S. surgeon general, wrote several years ago in the EPA Journal: "The insidious character of high-level exposure is such that it may be weeks, months, years, or decades before the total influence and reaction is felt." And Resnick says, "The squeaky wheel is going to get oil. Hearing loss has just not been squeaky enough."