Years ago, investigators were looking for a standardized stressing agent, something that would consistently cause abnormalities in animals. By accident they discovered that noise could produce the abnormalities they wanted: lesions in the urinary and cardiovascular systems, changes in the uteri and ovaries of female animals, alterations in the testicular structure of male animals. They also discovered that the acoustic stimulus could cause changes in the body's chemistry: an increased production of adrenal hormones, a decreased production of ovarian hormones, and other complex hormonal changes that influence fertility, growth, and other essential bodily functions.
Dr. Hans Selye pioneered a theory that the body produced these complex chemical changes to enable it to cope with stress. This stress reaction he described as the body's normal adjustment to an abnormal situation. However, when the stress is constant or too intense, the defense reaction itself becomes sufficiently extreme to be harmful. The adrenal glands become enlarged, the lymph tissues shrink, the stomach and intestines develop bleeding ulcers. He discovered that in patients who were under stress or tension from various sources, there appeared a number of vague, diffuse symptoms such as aches and pains, coated tongue, fever, and mental confusion.
Describing Dr. Selye's work, Saturday Review editor Norman Cousins wrote, "He has studied the effects of anxiety, stress and exhaustion on the adrenal glands. He reports a direct physiological connection between persistent tension and fear and the weakening of the total human organism. What happens, he finds, is that the supply of adrenalin runs dry and the body loses its chemical balance, or homeostasis...The effects of adrenal exhaustion vary all the way from physical crippling to heart disease."
Dr. Selye believes we are born with a limited amount of adaptation energy and that aging is a depletion of that energy. This could mean that excessive stress shortens life. And the Metropolitan Life Insurance Company, with an economic stake in longevity, says that one of the damaging side effects of stress is that it "may lead to disease, cause us to age prematurely, or sometimes even shorten life."
Certain diseases are designated as stress-activated diseases: the coronary, the ulcer, the irritable colon, the erratic blood pressure, the migraine headache, a great deal of mental illness, and what one doctor describes as "Selye's syndrome of 'just being sick.'"
When chickens are stressed with noise a complex physiological change takes place. Air-ground military maneuvers in the midst of North Carolina's largest poultry counties provided the necessary evidence. Chicken houses were subjected to the noises from planes, trucks, tanks, and foot traffic. "The roar of the motors and rotors combined with dust and air movement seemed most effective in exciting the hens," reported Dr. Douglas Hamm, poultry scientist. Egg production was down.
No one bothered to check for hearing damage among the chickens. It was assumed that the stress had its major effect on the central nervous system and hormonal system. While this is granted to chickens, it is not granted to humans, who must show hearing loss before others will accept the idea that noise has impaired their functioning.
Granted that a certain amount of stress is normal, and needed for survival, what happens when we ring the alarm bell too often?
Day and night, urban man's nervous system is getting false alarms from sirens, helicopters, jets, trucks, cars, motorcycles, with and without defective mufflers. The constant rain of noise can cause a state of stress. Ecologist Dr. Bruce Welch compares being forced to live in an environment of constant high-level stimulation to driving at high speed in second gear, or maybe in first. At the very least, a lot of energy is wasted, rejecting and reacting to unwanted sounds of excessive amplitude.
If the body is preoccupied with defending itself against constant physical and psychological stresses, its biological resistance to disease is lowered.
It should be noted that the diseases of yesterday—scarlet fever, polio, diphtheria—have given place to the unsolved problems of the chronic diseases such as arthritis, rheumatism, diabetes, cancer, cardiovascular diseases. Many of these diseases, incidentally, do not exist in the relatively noise- and other stress-free environment of primitive societies.
Urban man suffers from a host of ailments the causes of which are unknown, but for which rest and freedom from tension, both to prevent an attack and to prevent a recurrence, are prescribed.
One indication of the impact of noise on the nervous system is the fact that epileptic seizures are sometimes triggered by noises. It would seem more than coincidental that on October 16, 1966, the medicine section of The New York Times carried one story captioned "It's getting noisier," and next to it another, "Epilepsy on the rise." Noisy cities must be quite a tribulation to epileptics.
Dr. Jansen's studies at the Max Planck Institute have shown that noise bursts of 70 decibels and more caused pronounced bodily reactions which, he believes, could lead to illness if continued and high. In his pioneering study of a thousand steel workers, the group working in noisy conditions—more than 90 decibels—had a higher incidence of physiological and psychological disturbances than a comparable group working under quiet conditions (61 per cent as against 48 per cent). The noise-stressed group also revealed a 24 per cent incidence of heart irregularities as against 16 per cent for the "quiet" group. In Dr. Jansen's opinion, many industrial noise levels cause such undesirable reactions.
Among the acousticians who have noted a possible relationship between stressful noise and physiological damage is Los Angeles physicist Dr. Vern Knudsen, who has been studying and working with sound for some forty years. "I have always been sensitive to noise," he says, "and I even believe, though I have no proof, that my reactions to noise were significant in developing a series of ulcers in my duodenum. I knew that sudden noises cause violent stomach contractions, and I am convinced these contractions can exacerbate incipient peptic ulcers."
Dr. Knudsen is a physicist. What do physicians think about noise and ulcers? I once got into a heated argument with a doctor with whom I was associated on a noise-abatement panel. I did not want his medical report to place annoyance as the least important of the effects of noise, at least not without some disclaimer that annoyance did not mean inconsequential nuisance. The doctor was disturbed because he felt I was asking him to make statements about noise that were not scientifically supportable. However, he made this private admission: "I have had patients with ulcers. I knew in my heart that noise played a part, but I couldn't say anything about it. I couldn't prove it."
A Department of Agriculture review of animal studies reported experiments in which rats exposed to noise showed changes in the lining of the stomach, changes that could cause the appearance of gastric ulcers. Ten minutes of exposure to 80 decibels of noise followed by a twenty-minute quiet period produced a 37 per cent reduction in the number of contractions of the stomach. A noise intensity of 60 decibels or more reduced the secretion of saliva by about 44 per cent and also reduced the flow of gastric juices. Permanent abnormalities in such bodily functions can lead to more permanent types of injury, such as intestinal ulcers.
Diseases related to stress cannot be effectively controlled in a non-quiet environment. Arthritis seems to be one such disease.
No one knows the cause of arthritis. It can develop, according to the Arthritis Foundation, when there has been no injury, no overwork of the joint, no infection. Worry and fatigue may increase the severity of the symptoms. Many patients notice the beginning of rheumatoid arthritis symptoms following a disturbing experience. University of Rochester medical researchers have reported that rheumatoid arthritis victims had stressful experiences preceding an attack.
Though freedom from noise is never mentioned, woven in and out of the program for the prevention and cure of arthritis is rest, rest for the inflamed joint, rest for the whole body, generally in bed. The treatment for acute attacks of rheumatic fever includes rest. I wonder what it was like to have arthritis on upper Sixth Avenue?