The Sonics Boom

The Building is on a Military Installation somewhere in the United States. It is a most inhospitable building. It has no windows and only one entrance, heavily guarded. Its administrators obviously don't want the public to know what goes on inside, and perhaps this is kind of them. Inside are nightmares.

In one of the large laboratory rooms, two physicists and a biologist stand about a heavy metal table. They wear thick ear pads. On the table is a dial-covered device about the size and shape of a television set, with a trumpet-like horn protruding from its face. The device is a kind of siren, designed to produce high-frequency sound of outrageous intensity. The scientists are studying the effects of this sound on materials, animals and men. They are wondering if sound can be used as a weapon.

A small delegation of official visitors from Washington shuffles nervously into the room. The visitors are supplied with ear protectors and settled in chairs behind the siren. The physicists turn the device on and tune it in. A colossal high-pitched shriek fills the room. This is the audible component of the generated sound. It is loud enough to hurt the padded ears, but it is only a whisper compared with the main body of the generator's huge yell. The main body is in a higher range of frequencies--higher than the human ear can hear.

One of the physicists begins the demonstration by picking up a wad of steel wool with a tonglike instrument on a long pole. He holds the steel wool in the invisible beam of sound that issues from the horn. The steel wool explodes in a whirling cascade of white-hot sparks.

Next he picks up a flashlight and turns it on. He wants to show what an intense sound field might do to an enemy's delicate electronic gadgetry--the guidance mechanism of a missile, for example. He holds the flashlight in the beam. The light goes out instantly. A fraction of a second later, the glass faceplate shatters.

The biologist has brought a white rat into the room in a small cage. The rat is running around the cage, looking unhappy about all the noise. But his worries don't last long. The biologist lifts the cage into the sound field. The rat stiffens, rises up to the full stretch of his legs, arches his back, opens his mouth wide and falls over. He is dead. An autopsy will reveal that he has died of instant overheating and a massive case of the bends. There are bubbles in his veins and internal organs.

Such is the power of sound. And such is the state of sonics technology in the 1960s.

Sound has been a part of human life and death since prehistoric man used it to track his meals and warn him of danger, and scientists have been interested in it since Pythagoras first tried to figure out the mathematics of musical intervals some 2500 years ago. Yet until the past few years, the science of sound was distinctly low-caste. It had a grubby, hangdog air. Most of the men who pondered it down through the centuries--Francis Bacon, Isaac Newton, Albert Einstein--were men whose main interests lay in other, more glamorous fields. The few men who did concentrate on sound were regarded by most other scientists as unimportant, if not actually nuts.

Nobody gave them any research grants or set them up in expensive laboratories. They had to improvise their own equipment. In the 19th Century and early 20th Century, for instance, three separate teams of French experimenters studied the speed of sound and other phenomena by going underground and sending noises through water pipes and drainage conduits beneath Paris. The miles-long mazes of pipe served the purpose, but the scientists became damp and irritable. A Paris gendarme, hearing strange sounds from a street grating one night, peered into the hole and saw a man squatting below with a lantern and a flute. The man was scientist J. B. Biot, studying some mysteries of musical pitch. "What are you doing down there?" asked the gendarme. "Playing a flute, of course," snapped Biot.

Men like Biot spent much of their time trying to convince the scientific world that they deserved to be listened to. This only made things worse. Professor Dayton Clarence ("Shockwave") Miller, a founding father of the Acoustical Society of America, used to stomp around what is now the Case Institute of Technology in the 1930s with a copy of a 1929 history of science under his arm. "Look at this damned book!" he'd howl, waving it at anybody he could buttonhole. "It has more than five hundred pages, but there are only twelve lines devoted to sound!" His hearers would nod politely. "Gee, Professor," they'd mumble, "that's a shame." Miller later wrote a science-of-sound history himself. It promptly sank from sight in a vast silent sea of indifference--immersed so thoroughly that the New York Public Library's copies, now 30 years old, are still virginally free of thumbprints.

But times change. The science of sound began to get some attention during World War Two with the development of military applications such as sonar (Sound Navigation and Ranging) for tracking enemy vessels at sea. In the 1950s, studies of other sonic phenomena began to disappear one by one behind a shroud of military secrecy-- perhaps the most sincere honor that can be granted to any research project. And now, in the 1960s, the science of sonics is distinctly hot. It is glamorous, it is "in" at last. Big old companies such as Westinghouse and Goodrich have established sonics laboratories and are pouring money into them. More money is pouring in from the U. S. Government. New hot-shot sonics companies are springing up on all sides to cash in on the boom. There are acoustics societies and publications and awards and noisy conventions. Suddenly, everybody is fascinated by sound.

A lusty choir of sound-emitting gadgets has arisen to buzz, hoot, whistle and roar in the world's ear. Hospitals use high-frequency sound to clean instruments, dentists to clean teeth, nuclear submarine crews to shiver the rust off tools and scorched food off cooking pots. Athletic trainers use it to massage sore muscles. Surgeons use a more intense variety to detect tumors, remove warts, disintegrate parts of the brain in maladies such as Parkinson's disease. Lower-frequency sound is used as an anesthetic.

Companies big and small have staked their reputations and finances in the sound game. Honeywell and others have invented devices that send out sounds and, by analyzing the returning echoes, give characteristics of objects off which the sounds bounced. Such a device was used in 1965 to find a barge loaded with deadly chlorine gas that had sunk off Baton Rouge, Louisiana, and another will be used this summer by an MIT professor to find two lost ancient cities under the Mediterranean. Smith Kline Instrument Company, of Philadelphia, makes similar gadgets in miniature to detect trouble spots in the human body and to find foreign objects in delicate organs such as the eye. RCA has invented a typewriter that understands spoken sounds and will type anything you say to it. Ling Electronics of California makes a noise generator whose gigantic howl, loud enough to tear electronic equipment apart, is used to test the toughness of space-flight hardware. A New York store, Hammacher Schlemmer, sells a smaller noise generator that is supposed to drown out (with "white sound," a gentle hissing noise) other night sounds and help you sleep. And in case your neighbor's noise generator bothers you, B. F. Goodrich has invented a rubbery material called Deadbeat that stops sound almost completely.

Odd research projects are afoot. The U. S. Department of Agriculture is trying to find out why, in some cases, corn grows taller and cows give more milk when serenaded with music. The U. S. Navy wants to know why ship propellers sometimes sing (a lovely musical tone, but it interferes with sonar); what whales say to each other (they sound like morose cows); and how porpoises under the water and fishing bats over it use sonic echoes to home in unerringly on their prey. Scientists of the Bell Telephone Laboratories tried to discover how we identify an anonymous voice over a phone, and exactly why, and in what ways, music played in New York's Philharmonic Hall sounds different from that in the Mormon Tabernacle (one reason: The Tabernacle's builders used cattle hair to strengthen their wall plaster). The National Aeronautics and Space Administration wants to know what loud rocket noises do to people around a launching pad, and why such noises occasionally cause nausea, fainting and epileptic-like fits. University of Pennsylvania researchers are experimenting with high-frequency sound as a means of shaking slow-penetrating medicines into body tissues. Researchers at the Max Planck Institute in West Germany want to know why workers in noisy places such as iron foundries have more emotional and family problems than those in quieter places. Once-obscure subspecialties such as psychoacoustics (the study of how we hear a sound and what we do about it) and forensic acoustics (dealing with the growing number of noise-nuisance and ear-damage cases taken to court) are growing important enough to begin forming societies and holding conventions of their own.

"It's nice to be needed at last," says New Jersey sonics expert Lewis Good-friend. He is a dark, wryly humorous man who worked on sonic weaponry during World War Two and now has his own acoustics company, Goodfriend-Ostergaard Associates. The company earns its living by such means as designing quiet offices, determining the effects of noise on aircraft personnel, testing sound-deadening materials and appearing in court as an expert witness in noise-nuisance cases. It is a small outfit but--typical of the times--wealthy enough to afford a complete sound laboratory full of shiny equipment. Says Goodfriend contentedly: "In the last few years this business has gained status. It's hard to explain why, exactly. There haven't been any really revolutionary new discoveries. Most of the work being done today is a continuation or intensification of earlier work, but it sounds new because people never heard of it before and it wasn't used before. I can't say what caused this upswing, but I will say I like it."

Sound, the phenomenon that all the noise is about, is a wavelike disturbance in a solid, liquid or gas. The disturbance travels at about 1090 feet a second in air at sea level, roughly five times as fast in water and 15 times as fast in iron. It is unfortunate that we do most of our hearing in air, for air is one of the poorest conductors of sound. A detonated 50-pound dynamite charge can be heard for maybe ten miles in still air, but for more than 10,000 miles in water--which is why the U. S. Navy is hopefully developing equipment for hearing enemy vessels hundreds of miles away.

Sounds have two main characteristics: frequency and intensity. The frequency is the number of waves (usually called cycles) that pass a given point in a given time. The human ear and brain detect frequency as pitch--how "high" or "low" the sound is. An average young man can hear tones from about 15 cycles per second to 20,000 cps; but as he grows older, his upper threshold drops, and he may end his life virtually deaf to tones higher than 10,000 cps. Luckily for him, most music lies within that range. The lowest note of an organ (made by a pipe 32 feet long) is about 16 cps. The lowest A on a piano is 27 1/2 cps; the lowest note a basso can sing is about 80. A soprano can reach as high as 1200 cps; a piccolo, 4186; an organ (with a pipe less than an inch long), 8372.

Sensitivity to pitch differs from person to person. There are various degrees of "tone deafness," the inability to hear fine differences in frequency. At the other end of the scale are people such as piano tuners, who can hear the difference between an A tuned at 440 cps (the international standard) and 441 or 442 cps (which some orchestras prefer). Still more rare are the 25 people in a million with "absolute pitch," the ability to sound a perfect 400-cycle A or any other note from memory. "I've never thought about it much," says one man who has this rare knack, Connecticut musicologist-composer-organist-choir-master Dr. Robert Rowe. "I remember a note the way I remember your name. It's there when I want it, that's all."

Nobody knows why people's pitch sensitivity differs or where the gift of absolute pitch comes from. Some say it results simply from an unusually loud and steady ringing in the ears. You probably found this ringing especially loud the last time you had a fever. It's thought to be caused by miniature vibrations of ear parts. The interesting thing about it is that, in any one individual, it's usually about the same pitch. If you want to fake absolute pitch, you may be able to do it by using this ringing as your reference point.

Frequencies higher than the human hearing threshold are called ultrasonic. Dogs, bats, porpoises and other creatures can hear higher frequencies than humans--in some cases as high as 150,000 cps. "But this doesn't make them anything special," says an engineer of the Hewlett-Packard Company, which makes ultrasonic listening devices for detecting leaks in boilers and other pressure systems. "Hell, with a little ingenuity, a man can hear any frequency he likes." At the University of California, in fact, physicist Klaus Dransfeld has produced and recorded frequencies in the fantastic neighborhood of 20 billion cps. High frequencies like that are usually produced with piezoelectric crystals such as quartz, which change shape in an electric field. They can be made to hum ultrasonically by applying a rapidly alternating field.

The other main characteristic of a sound, its intensity or "loudness," is most often measured in decibels--which is unfortunate, for decibels are hard to talk about. The decibel scale is a logarithmic scale, not a scale of equal-sized units like inches or pounds. Every upward step of ten decibels represents a tenfold multiplication of sound energy. (continued on page 183) Sonics Boom (continued from page 114) Thus, a sound of 50 db is ten times as powerful as one of 40 db, and one of 100 db is a million times as powerful.

When acoustics professors are trying to wake up sleepy students, they like to say that the softest sound the human ear can hear is that of a baby mouse urinating on a dry blotter three feet away--roughly one decibel. Modern super-sensitive microphones made by Bell Telephone, General Radio and others can hear much softer sounds. They can clearly pick up, for example, the noise made by a Kleenex fluttering down and hitting a solid concrete floor 50 feet away. A spy on the sidewalk outside a ten-story building can hold such a microphone against the wall and--if it's nighttime and there are no loud noises in the building--hear a conversation being held on the top floor.

But most human hearing experiences come from much louder sounds. Dry leaves rustling in a breeze produce about 10 db; ordinary conversation, 60; a full-volume discothèque, about 80. The discothèque volume is about the loudest that the ear can take for a long time without discomfort. The loudest sounds we're normally subjected to are about 10,000 times more intense, up in the range of 120 to 130 db. This is the range where sound begins to cause physical pain and deafness. Sounds like these are manufactured by such companies as the Leslie Company, the nation's biggest maker of foghorns and ship whistles; and Federal Sign and Signal Corporation, the biggest maker of sirens. The Queen Mary's whistle, says Leslie, produces 123 1/2 db at a distance of 100 feet (the standard distance for measuring such noisemakers). A big-city air-raid siren clobbers the ears with 125 db. A large Coast Guard foghorn has about twice that power: 128 db.

A sound that big can cause temporary or permanent deafness, depending on its duration and frequency (the ear is most sensitive to sounds in the middle and upper range of a piano). It can also cause other odd effects, such as blurred vision from oscillation of the eyeballs.

Louder sounds cause still odder effects. A decade and a half ago, a scientific group at Pennsylvania State College made a shriek so colossal that it could brew coffee, smash insects and kill mice. "On looking back, I find the whole set of experiments kind of macabre," says the chief noisemaker, physics professor Isadore Rudnick, now at UCLA. "We were developing intense sound sources. At that time, almost nothing was known about the effects of intense sound on humans. Occasionally we'd remind ourselves of the early days of radioactivity, when researchers unknowingly exposed themselves to crippling doses, and we worried."

To find out what a big sound might do to people, besides deafening them, Professor Rudnick and his colleagues built the most powerful siren ever conceived to that date. It made what was, as far as anybody knew, the loudest continuous sound ever heard on earth up to that time: 175 db, some 10,000 times as strong as the ear-splitting din of a large pneumatic riveter. The frequency range of this enormous howl was from about 3000 cycles per second (near the top range of a piano) to 34,000 cps, in the ultrasonic range.

Strange things happened in this nightmarish sound field. If a man put his hand directly in the beam of sound, he got a painful burn between the fingers. When the siren was aimed upward, 3/4-inch marbles would float lazily about it at certain points in the harmonic field, held up and in by the outrageous acoustic pressure. By varying the harmonic structure of the field, Professor Rudnick could make pennies dance on a silk screen with chorus-line precision. He could even make one penny rise slowly to a vertical position while balancing another penny on its edge. A cotton wad held in the field would burst into flame in about six seconds. "To satisfy a skeptical colleague," reports Professor Rudnick, "we lit his pipe by exposing the open end of the bowl to the field."

The researchers were careful to keep themselves out of the ghastly sound beam, and they wore ear plugs and pads. All the same, they were troubled by odd physical effects while working next to the beam. They were plagued by dizziness and blurred vision. Fatigue set in quickly. There were tickling and "sizzling" sensations in mouths and noses, sometimes acutely disagreeable.

Working with the group was Dr. H. Frings, a zoologist interested in pest control. He discovered that a mouse exposed to the colossal sound died in about a minute, mainly of internal overheating. Insects were virtually disintegrated in ten seconds. According to the research team's report, a typical mosquito suffered the following catalog of misfortunes: "Both wings completely shattered. Abdomen full of bubbles. Body badly battered. Scales gone. Antennae in very bad shape..."

A scream like that is a potential military weapon, and since the mid-1950s, such supernoisemakers have been muffled in secrecy. "There's no question that a loud sound can do damage, or at least could be used to disorient enemy troops or flush them out of a hiding place," said an Army officer one night recently in Washington, gazing pensively into a martini. "The question is, would such a weapon be practical? It takes a lot of power to generate a damaging sound. Bullets are a lot cheaper, you know."

Still, superscreams are now being generated in military labs. Robert Gilchrist, president of Federal Sign and Signal, tells of tantalizing rumors that have circulated in the noisemaking business over the past few years. "We just heard about a siren of some kind, supposedly intended for Vietnam," he says. "It's said to produce something like 200 decibels." That would be several hundred times as powerful as Professor Rudnick's monstrous screamer.

Gilchrist is a quiet man who escapes from his loud business by eating in quiet restaurants. Setting down his coffee cup with care so as not to make it clang on the saucer, he starts to tell of cases in which his company's small civilian sirens have been used as weapons. "There was a case in Illinois a few months ago," he recalls. "A race riot. The local police broke it up by simply driving their cars into the mob with the sirens going. A sound like that is like a bucket of cold water in the face: It breaks a man's train of thought. The rioters couldn't pay attention to what they were doing. They stopped fighting and just milled around. The police got the two gangs separated and drove them in opposite directions with the sirens--actually pushed them down the street with sound."

The subject of sonic weapons is a touchy one. If you ask questions on a sober morning in the Pentagon, you receive dry chuckles in reply. "Sonic weapons? Haw, haw. You've been reading too much science fiction, pal!" But questions asked of big organizations such as MIT, the Bell Telephone Labs and RCA reveal the oddly contradictory information that all have Government sonics contracts that they aren't allowed to talk about. Some of these contracts have to do with well-known military applications of sound such as sonar and other echo-ranging systems. Other sonics research is more bizarre.

The Nazis in World War Two were interested in the military promise of sound, though they were never able to use it effectively. Early in the War, they experimented with attachments that would make bombs and artillery shells scream, moan and warble. The hope was that these loud sounds would make troops and city populations panic. It didn't work, except on small children. Toward the end of the War, as the Reich ran out of ammunition, reports circulated that German bombers were dropping beer bottles. The bottles made a high-pitched shriek as they fell, the reports said, and were obviously intended as a scare weapon. Two American scientists, Harold Burris-Meyer and Virgil Mallory, investigated the rumor. Mallory stood on the shore of a small lake in New Jersey one afternoon, and Burris-Meyer flew over in a plane and dropped bottles of assorted sizes and shapes into the lake. "I heard no sound that was remotely frightening," reported Mallory. "In fact, it was quite a pleasant musical afternoon."

Near Dachau, site of the notorious concentration camp, a team of Nazi scientists experimented with the use of powerful sirens to control groups of people. The hope was that, if a sound could be made loud enough, it could be used to disorient or paralyze enemy troops in certain battlefield situations. There may have been more sadism than science in these experiments, for the only known results were that several Jews used as test subjects were deafened.

Research since then has been more useful. At an Air Force medical lab in Ohio, for instance, a group led by Dr. Henning F. von Gierke has been making similar studies of the effects of sound on man. Dr. von Gierke's main concern is with the unwanted effects of loud aircraft noises and other 20th Century sounds on the Air Force's own men, but military planners have watched this and related studies with an eye on weapons possibilities.

One rather weird finding to come from such research is that various parts of the human body resonate to certain frequencies of sound. (A resonance is an answering vibration: Hold a banjo near a piano and play an A on the piano, and the banjo's A string will sing.) Some body resonances are mildly uncomfortable. Some are worse.

In New York recently, an acoustics engineer demonstrated one such resonance to a group of Columbia University students. He sat them in a room and bombarded them with massive sound at a frequency of about 75 vibrations or cycles per second--roughly the pitch of the next-to-lowest D on a piano. Within seconds, half the men were hurrying out of the room. Seventy-seven is the frequency at which the average human anal sphincter resonates. When it resonates hard enough, it can no longer be controlled.

Such a sound could conceivably be used to demoralize enemy troops--or, more likely, to cool off mobs and quell riots. It would be a weapon with a sense of humor--certainly with a bigger smile than other police crowd-control weapons, such as cattle prods, night sticks, fire hoses and tear gas. "Any such weapon will have to wait for another step forward in sound-making technology before it's practical," says Lewis Goodfriend. "At present it's too expensive to make big sounds." All the same, at least one siren-making company is now reportedly experimenting with a huge low-frequency boomer for crowd control.

Other body resonances have other effects. A New York journalist, George Riemer, recalls a pilgrimage he made to the Newport Jazz Festival in Rhode Island some years ago. At one late-night party, among other interesting sights, he saw a girl lying ear-down on the floor next to an enormous bass fiddle. The bass man was playing, watching the girl with interest. Riemer squatted down to find out what was going on. "Aren't you afraid you'll get stepped on?" he asked the girl.

She looked up at him dreamily. "That's the chance I take," she said. "It turns me on. I get it through the floor. I mean, it turns me on!" A year later, Riemer heard that she had married the bass man.

There is much that still has to be learned about sound and the human response to it. Another odd effect, not at all clearly understood, is that a loud sound can drown out other body sensations, such as pain. A dentist in Cambridge, Massachusetts, a big, genial man named Dr. Wallace Gardner, chanced on a way to use this effect in 1958. He had a patient named Joseph C. R. Licklider, a psychologist from the acoustics firm of Bolt, Beranek and Newman. Licklider didn't like the sound of a dental drill, and he theorized that patients might be happier in the chair if they couldn't hear that menacing whine. Together, Gardner and Licklider developed gadgetry for masking the sound. The cringing patient put on a pair of earphones. By turning knobs in a control box on his lap, he could hear either tape-recorded music or white sound. He could turn the sound up to thundering volume if he liked.

First Licklider and then other patients tried the idea. To Dr. Gardner's surprise, they reported that they not only couldn't hear the drill, they couldn't feel it, either. Somehow the sound masked the pain. A year later, Dr. Gardner for the first time pulled a man's tooth with no anesthetic other than sound. The man listened to white noise and a Beethoven symphony and reported feeling perfectly comfortable during the operation. Today, dentists throughout the country use this "audio-analgesia." It doesn't work with everybody, but it works so well with some that dentists have used it to pull entire mouthfuls of teeth without hearing a word of complaint.

Why does it work? Nobody knows. Dr. Gardner's theory, supported by some psychologists, is that there is a limit to the human brain's sensation-receiving capacity. If the brain is receiving a huge amount of sound, it may have little capacity left to receive pain sensations.

Sound may also leave the brain little-capacity to think. This is why a siren can break up a riot--and it is also why people who live or work in cities, or in industrial plants or near airports, are making more and more noise about the noise. "The more technology advances," says Frederick Van Veen of General Radio Company, which makes sound-measuring instruments, "the noisier it gets. And the noisier it gets, the harder it is on people who work with their brains."

Van Veen took one of his company's noise-level meters to Manhattan one day recently. He wanted to know the extent to which city noise in the mid-1960s interferes with conversation, and he had his meter set to pay special attention to frequencies of sound that interfere most with talk. With this setting, any sound clocked at 70 db or more is one that will require some degree of shouting or will drown out words entirely. On a sidewalk at the corner of 47th Street and Second Avenue, Van Veen got readings of 70 to 74 db. This was at 2:30, a relatively quiet time of afternoon. In a bus going through a tunnel, he clocked 75 db. On a subway platform, ten feet from a passing train, he read 90 db.

Citizens of New York and other big cities don't really need decibel readings to tell them noise levels have been rising. One summer morning last year, an angry Manhattanite, tormented beyond endurance by the vast cacophony of his city, rose from his bed, ran outdoors and jammed a noisy Sanitation Department man head-downward in a garbage can. "I'll make this goddamn city whisper!" he roared. "All right, all right," said the mournful voice in the can, "quit shouting."

Cities have always been noisy. The Greeks of ancient Sybaris arrested people for shouting in the streets. The Romans told dirty jokes about the Sybarites' sensitive ears, holding that Rome's noise was proof of its virility; but Juvenal, Cicero and other thinking Romans had to flee to the country to get any work done. In later times, Marcel Proust paneled his study with cork to shut out the "terrible voice" of Paris. Charles Babbage, 19th Century English mathematician who fathered the modern digital computer, made himself notorious with incessant complaints about the noise of London. Bands of street musicians would come miles out of their way to play gleefully beneath his window. He and his ladyfriend, the Countess of Lovelace, a daughter of Lord Byron, pelted the musicians with rotten fruit and meat bones. "God, oh God, why did you give me ears?" Babbage would howl.

If things were bad then, they're nearly intolerable now. It's estimated that the average noise level of the average city has increased by about one decibel per year for the past 30 years. This has caused all kinds of problems. Constant noise damages the hearing. It robs people of sleep. It makes them irritable. The World Health Organization in 1966 warned that "noise pollution" is one of the worst health hazards in cities all around the globe. Some psychiatrists have even suggested that the past decades' increases in violent crimes, common to cities of all industrial nations, may have resulted at least partly from too much noise. "Even such a thing as interrupted sleep may be dangerous," a psychiatrist told a New York mentalhygiene committee in 1966. "If people are prevented from dreaming, severe psychotic symptoms may appear." Noise, in short, drives people nuts.

The need for at least occasional quiet seems to be universal among animals. Some years ago, two psychologists rigged up an experiment to show that man is not the only creature with an altruistic love for his fellow creatures. They hung a rat by his tail. He squealed. Other rats in the cage could lower him to the floor by pushing a release lever, and after a little practice, they learned to do this as soon as they heard their buddy squealing. "Aha, altruism!" said the psychologists. A year later, two other psychologists at the Defence Research Medical Laboratories in Toronto duplicated the experiment. But instead of hanging a rat by the tail, they used recordings of white noise. The rats learned to push a lever and stop the noise even more quickly. Conclusion: altruism, shmaltruism. The rats just couldn't stand the damned noise.

B. F. Goodrich, maker of Deadbeat, has recently been publicizing a guess that noise costs the nation's industries $2,000,000 a day in decreased human efficiency and in compensation for injuries (not only damage to the ear but also injuries resulting from not hearing a danger signal or warning shout). Things are bound to get worse before they get better. California and a few other states, New York and a few other cities, have recently passed noise-limiting laws, but these are only now in the stage of being tested in court. While the tests go on, technology will get noisier. In about two years, to mention only one example, supersonic jet airliners will probably be flying over our already noisy towns and cities. A plane flying faster than sound (660 mph at an altitude of 35,000 feet) causes a sonic boom, a shock wave that is sometimes loud enough to break windows. Sonics experts have spent years trying to find a way to eliminate this jarring noise, but they're no closer to a solution than when the first booms were heard in the United States in the early 1950s.

"There's a lot to be done in this business," Lewis Goodfriend told a reporter recently, as they strolled down a sidewalk on the way to lunch. "There are two big avenues of research: learning how to use sound and learning how to get away from it when it isn't wanted. Actually, I think we're just on the threshold of----"

But it was 12 o'clock, and a noon whistle began to screech from a building nearby, and the rest of Goodfriend's words were lost in the din.