The Tyranny of Noise

Robert Alex Baron

Part II — Chapter 5 — The Price In Environmental Quality

Perhaps the most dramatic example of how commerce and technology are defiling our environment is provided by the advent of the supersonic transport, the needle-nosed SST.

Fear of what the SST will do to man and his environment is being increasingly voiced by scientists and government officials alike. Don Dwiggins, for many years the aerospace editor of the Los Angeles Mirror News, in 1968 wrote a book, The SST Here It Comes, Ready Or Not. At the end of this carefully documented work, he told his readers that he had discovered the villain of his story to be "the SST itself."

Why all the concern about this new type of plane, while the prosaic noises of surface transportation and even the subsonic jets have yet to arouse the public—or government—to effective action?

The reason is an eerie phenomenon spelled b-o-o-m, sonic boom—a physical reaction to the rupturing of the sound barrier as an airplane travels faster than sound. This boom is not something that happens only once, when the plane breaks the sound barrier. The sonic boom, somewhat like the wake of a ship, is a "sonic carpet" that accompanies the plane as long as it flies supersonically. As described by Dr. Bo Lundberg, a Swedish aviation authority, the conical pressure wave becomes strong and hits the ground in every spot within a "boom carpet" which stretches miles wide continuously along the entire flight path. The typical boom is a shock wave, caused by the air compressed by supersonic flight. The wave of compressed air exerts physical pressure against whatever stands in its path.

We do not as yet know what the commercial sonic boom will be like. But we already know what booms from smaller supersonic planes will be like. We have a Canadian military pilot to thank for giving us some inkling of what the boom can do to structures. Flying an F-104 supersonic jet fighter, he accidentally flew supersonically at an altitude of 500 feet. Nothing much might have happened had he been flying over the desert, but he was flying over the temporary control tower and the terminal building of the almost-completed Ottawa airport.

Don Dwiggins, in his book on the SST, summarized what happened to the structures:

With a mighty concussion the control tower literally exploded, showering glass in all directions. The terminal roof was ripped open and aluminum flashing strips were thrown across the access road. A curtain wall over the ticket lobby was distorted. Large glass panes in the terminal were smashed. Four doorways suffered severe damage. Exterior stucco broke away, and crashed to the ground.

Throughout the new building the ceiling was blown apart, the recessed fluorescent fixtures left skewed, pushed up, or left hanging down, as if wrenched and tortured by a severe earthquake.

It cost the government of Ottawa $300,000 to repair the damage. The flight pattern, was, of course, against the rules.

It may be argued that this was an accident, but even in normal operation the sonic boom has a destructive effect on natural and man-made structures. In 1968, reports of damage to cliff dwellings in the National Parks System prompted the then-Secretary of the Interior Stewart Udall to initiate his own study of the boom. Park engineers reported damage in Canyon de Chelly National Monument in northeastern Arizona and to geological formations in Bryce National Park in Utah, and potential damage to Mesa Verde National Park in Colorado. An estimated 80 tons of overhanging cliff fell on a cliff dwelling in Canyon de Muerto.

The Interior Department's 1968 sonic boom report (Udall) leaves little room for complacency. The scientists who wrote the report observed that unlike subsonic jets, which impact an area basically within a radius of 12 to 15 miles of airports, the SST, even if flown at high altitudes, creates new noise corridors on the ground tens of miles wide along its flight path so that "...potentially no land area would be free from some noise intrusion."

Dr. Lundberg was the first to warn the world about the meaning of the sonic boom. He believes that "in the supersonic age it will be inadvisable to take a siesta, or leave a child in a pram, on a balcony, or beside a garden wall." Thanks to military supersonic flight, at least one French family didn't have to wait for the supersonic age of commercial aviation. Here is the havoc as described by Walter Sullivan, Science editor of The New York Times: "Last week a French farm family, with eight neighbors and hired hands helping in the harvest, gathered for the noon meal in a farmhouse near the village of Mauran in Brittany. Suddenly, according to accounts from France, a sound like a thunderclap was heard. Timbers shook loose and eight tons of barley stored in a loft fell on those eating, killing three and injuring one seriously. Apparently it was the first time that a sonic boom had been blamed for fatal injuries."

Apparently these Bretons didn't know enough to adapt to one of the new "minor stresses" of modern living.

Understandably, then, there is a raging controversy over whether or not the SST should be permitted to fly at supersonic speeds over land. If such flights are permitted, according to the Udall study, sometime after 1975 between 20 million and 40 million Americans would be boomed five to fifty times a day under a path 12½ miles to either side of the flight paths. An additional 35 million to 65 million people within a path 12½ to 25 miles to either side of the flight path would be subjected to from one to fifty booms per day of somewhat lower intensity, and 13 million to 25 million more would experience one to four high-intensity booms. In short, up to 130 million Americans a day would be exposed daily to the boom.

According to the Interior Department study, here is how people react to sonic booms:

"...There is considerable initial adaptation following several months of exposure, but even after several years of experiencing booms, most people find the booms objectionable or worse. Extensive research at Edwards Air Force Base, Oklahoma City, and in France, shows that even after some years of continued exposure to sonic booms, 30 per cent of the people exposed to booms at levels anticipated fcr the SST would find the booms to be 'intolerable' or 'unacceptable' and an additional 50 per cent would find them 'objectionable.'

"Persons experiencing sonic booms are startled and diverted or, if asleep, may be awakened in the same manner as those who hear an unexpected loud thunderclap or a large explosion. These effects may be accompanied by increased pulse rate and other minor and transient physiological changes, but they are not believed to be harmful in themselves, nor to endanger hearing."

It should be noted that in the body of this study it is admitted that "No tests on experimental animals or on human beings have been conducted over a sufficiently long period of time to detect possible chronic effects, or effects of long-repeated exposures to sonic booms...Tests conducted to date have not explored fully many of the situations in which sonic boom annoyance might be amplified. How extensive, for example, would be the interruption of cultural and artistic activities in which quiet and concentration are important? What is likely to be the impact upon infants, sleeping children, hospitalized persons or other individuals whose immediate well-being requires uninterrupted sleep or freedom from excessive noise? Studies to date have not considered these kinds of situations."

In his documented source book on the SST and the sonic boom, William A. Shurcliff, Ph.D., Director of the Citizens League Against the Sonic Boom, provides further information on why the sonic boom is a new noise, to be taken seriously:

"The boom is annoying because it is so loud, so sudden, and occurs with no warning whatsoever. It sounds much like the 'bang' produced by a moderate-size explosion a block away. Because it strikes with no warning (and no visible explanation), the boom evokes man's primitive startle reaction...The surgeon making a delicate incision will jump too."

This source book further describes the adverse effect of noise on sleep. During the Oklahoma City sonic boom tests (sponsored by NASA and the FAA), "18 per cent of the persons polled complained of sleep-interference by the boom—even though the booms did not start each day until 7:00 A.M., and even though the average overpressure of the booms was only 60 per cent of the overpressure expected of [commercial] SSTs' booms. Many persons used the 7:00 A.M. boom as an 'alarm clock'—and did not 'get used to it.'"

Hidden in the government reports of sonic boom tests is the word "average." The reference is to the average boom pressure. The incidents reported above were presumably caused by the average type of sonic boom. But Dr. Lundberg has called attention to the "superbang," a sonic boom that exceeds the average pressure by a multiple of two or more. In the tests conducted at Oklahoma City, Lundberg observed that "at every point within the whole carpet, one boom strike in a thousand is twice as strong or more than the average on the track." Many factors contribute to the formation of a superbang: atmospheric conditions such as temperature changes, winds, local turbulence, cloud formations, flight operations such as turns and accelerations. It does not look as if local or even Federal laws will stop these.

Though only one boom in 10,000 is likely to be a superbang, they will be frequent occurrences because of the millions of people and structures that will be struck in the boom carpet. Lundberg believes that conservatively speaking, 10 million people could be exposed to superbooms in the boom carpet of the New York-to-Los Angeles run. He further believes that this enormous mass of severe boom strikes will inevitably result in many serious accidents, for example by falling glass, or even deaths, by heart failure.

If overland flights are banned and supersonic speed permitted only over water, how easy will it be for commercial fishermen, and steamship passengers and crew, to settle their claims for sonic boom damage?

How effective will protest be, even if 50 million are boomed? Only a small minority will know how to or be prompted to protest. Also, it will be much simpler to repatch the plaster than to go through the red tape of processing a complaint against the government.

Replying to those who say we must accept the sonic boom as another noise stress, Lundberg says it is illogical and cynical to ask us to accept the sonic boom just because we suffer from jet, traffic, and other noises. "The very fact that local noise is unavoidable these days, makes it, of course, all the more important that the countryside and quiet suburbs are kept undisturbed. Only then will it remain possible for those who are noise ridden during part of the day to recover in the evenings and nights and during weekends, holidays, and sickness."

Meanwhile the international race to introduce the SST continues.