The Effects of the Physical Environment on Children’s Development

Not just loud or sudden noises provoke a stress response. Chronic low-level noise also negatively influences the brain and behavior. Whether from the road or in the office, low-intensity noise has a subtle yet insidious effect on our health and well-being.

Noise at home or school can affect children's ability to learn. Compared to kids from quieter neighborhoods, children living near airports or busy highways tend to have lower reading scores and develop language skills more slowly. Psychiatric hospitalizations are higher in noisy communities.

Bad moods, lack of concentration, fatigue, and poor work performance can result from continual exposure to unpleasant noise. [Family Circle, November 1991]

According to Dr. Alice H. Suter, an audiologist at the National Institute for Occupational Safety and Health: "Included in noise-related problems are high blood pressure, peptic ulcers, cardiovascular deaths, strokes, suicides, degradation of the immune system, and impairment of learning.

Noise is also associated with an increase in aggression and a decrease in cooperation." [New York Times, March 6, 1990]

Even everyday traffic noise can harm the health and well-being of children. In the first study to look at the non-auditory health effects of typical ambient community noise, it was shown that chronic low-level noise from local traffic raised levels of stress hormones in children, as well as their blood pressure and heart rates.

"We found that even low-level noise can be a stressor. It elevates psychophysiological factors and triggers more symptoms of anxiety and nervousness," says environmental psychologist Gary Evans of Cornell University, an international expert on environmental stress, such as noise, crowding, and air pollution.

Evans and his European colleagues analyzed data on 115 fourth-graders in Austria. Half the children lived in quiet areas – below 50 decibels (dB), the sound level of a clothes dryer or a quiet office. Half lived in a noisier residential area – above 60 dB, about the intensity of an average dishwasher or raised voices.

"We are really not looking at loud kinds of noise. They are typical levels found throughout neighborhoods in Europe," says Evans. The non-auditory effects of noise, however, appear to occur at levels far below those required to damage hearing.

The children in noisier neighborhoods experienced higher overnight levels of the stress hormone cortisol, marginally higher resting systolic blood pressure, and greater heart rate reactivity to a stress test – all signs of modestly elevated physiological stress.

"Anything that increases blood pressure, for example, has negative implications for long-term health effects," says co-author Peter Lercher, M.D., an epidemiologist at the Institute of Hygiene and Social Medicine at the University of Innsbruck. Elevated blood pressure in childhood is thought to predict higher blood pressure later in life.

Background noise had a significant effect on stress levels, said Lercher. Therefore, chronic exposure to nearby sounds from roads and train lines are a concern.

The study adds evidence to Evans' previous research showing that noise can have serious health, learning, and task-motivation effects in children and adults exposed to chronic noise. "The findings suggest that children living in noisier areas are subject to stress, which may have serious health implications," conclude the researchers. [Journal of the Acoustical Society of America, March 2001]