Unwanted sound. The Oxford English Dictionary contains references to noise as unwanted sound dating back as far as 1225.
Unmusical sound. The nineteenth-century physicist Hermann Helmholtz employed the expression noise to describe sound composed of nonperiodic vibrations (the rustling of leaves), by comparison with musical sounds, which consist of periodic vibrations. Noise is still used in this sense in expressions such as “white noise” or “Gaussian noise."
Any loud sound. In general usage today, noise often refers to particularly loud sounds. In this sense a noise abatement by-law prohibits certain loud sounds or establishes their permissible limits in decibels.
Disturbance in any signaling system. In electronics and engineering, noise refers to any disturbances which do not represent part of the signal, such as static on a telephone or snow on a television screen.
The matter is more complex than this. For instance, while the word noise was first used in English to imply “unwanted sound,” it frequently took on a richer meaning and was sometimes used to imply “an agreeable or melodious sound.” Chaucer uses it this way in his translation of the Roman de la Rose.
Than doth the nyghtyngale hir myght
To make noyse and syngen blythe. (11. 78-79)
Of whiche the water, in rennying,
Gan make a noyse ful lykyng. (11. 1415-16)
The King James version of the Bible also employs the word noise in a broad sense:
Make a joyful noise unto the Lord, all ye lands. (Psalms 100:1)
While this wider connotation has disappeared from the English word today, it still exists with the French equivalent, bruit; for the Frenchman may still refer to the bruit of the birds or the bruit of the waves, as well as to the bruit of the traffic. One of the difficulties in dealing with noise internationally is that the word has slightly different nuancing in each language. I have also employed the word in a wider context in the expression “Sacred Noise” (see pages 51-52 and 114-115).
Of the four general definitions, probably the most satisfactory is still “unwanted sound.” This makes noise a subjective term. One man’s music may be another man’s noise. But it holds out the possibility that in a given society there should be more agreement than disagreement as to which sounds constitute unwanted interruptions. “To disturb the public” then means to disturb a significant portion of the public, and it is in this manner that traditional legislation usually deals with noise problems. Such noise legislation may be called qualitative, inasmuch as it involves public opinion.
This contrasts with another type of legislation called quantitative. Such legislation sets decibel limits to specified undesirable sounds. If, for instance, a regulation states that the permissible level for an automobile is 85 decibels, an automobile producing 86 decibels is noisy while one producing 84 decibels is not noisy—or so the law would have us believe. The quantitative measurement of sound is thus tending to give noise a meaning as “loud sound.” This is unfortunate because, as we know, not all irritating noises are necessarily loud, or at least loud enough to show up effectively on a sound level meter. Noise has come to be evaluated quantitatively owing to the risk of hearing loss, a matter about which enough is known for definite prevention criteria to have been established. It is, therefore, a subject that should be clearly understood.
The Hazards of Noise Medical science has determined that sounds over 85 decibels, heard continuously over long periods of time, pose a serious threat to hearing. The resulting malady is often referred to as boilermaker’s disease, because the earliest known victims were workers in factories where metal boilers were riveted together. Prolonged exposure to sound beyond this level may result, first, in temporary threshold shift (or ITS as it is sometimes called). TTS is an elevation of the threshold of hearing so that after being subjected to a very noisy experience, all sounds heard afterward seem fainter than usual. Normal hearing returns after a few hours or days. With further exposure, permanent cochlear damage may take place, resulting in permanent threshold shift (PTS). When this loss occurs in the inner ear, it is incurable.
Authorities concerned with industrial hygiene are now attempting to fix and enforce hearing risk criteria. In the U.S.A. a great step forward was taken when the Walsh-Healey Act of 1969 stipulated that no government contracts would be awarded to industries not respecting the established criteria. These were somewhat above the recommendations of the American Otological Society, and represented a compromise between the ideal and the immediately practicable. These recommendations parallel criteria already in effect in numerous European countries.
Permissible Noise Exposure
as Established by the Walsh-Healey Act (1969)
DURATION PER DAY
(HOURS) SOUND LEVEL
(dBA)
8 90
6 92
4 95
3 97
2 100
1½ 102
1 105
½ 110
¼ or less 115
The threat of industrial hearing loss is now being resisted and is therefore not a concern of these pages. But PTS and TTS are by no means limited to these precincts. For instance, some researchers have found that exposure to levels as low as 70 dBA for 16 hours daily may be sufficient to cause a hearing loss. This is substantially lower than curbside traffic on a busy street. The term sociocusis has been devised to refer to non-industrial hearing loss, and a large number of examples could be given in illustration. For instance, it has been established by audiometric examination that persons operating power lawnmowers averaging 97 dBA suffer a temporary hearing loss after 45 minutes of exposure. We have already encountered a similar problem resulting from snowmobiles (Chapter Five) and amplified music (Chapter Seven). When Dr. George T. Singleton tested 3,000 public school children in Florida, he discovered a marked decrease in high-frequency hearing as the student progressed from the sixth to the twelfth grade, a period during which students had been exposed to rock bands, motorcycles and other “recreational” noises. Dr. Singleton and others found that the hearing ability of college freshmen who had attended rock concerts often deteriorated to that of sixty-five-year-olds.
Because sound is vibration it affects other parts of the body as well. Intense noise can cause headaches, nausea, sexual impotence, reduced vision, impaired cardiovascular, gastrointestinal and respiratory functions. But noises need not be intense to affect the physical state of humans during sleep. Russian researchers have found that “the level of thirty-five decibels can be considered as the threshold for optimum sleeping conditions …” and that “when noise is at a level of fifty decibels … there are fairly short intervals of deep sleep … followed, on waking by a sense of fatigue accompanied by palpitations.”
Everyone’s hearing tends to degenerate a little with age. This happens very gradually and begins first in the high frequencies, which is the reason older people sometimes complain “everyone mumbles nowadays.” This gradual loss of hearing acuity due to age is called presbycusis. It has always been assumed that presbycusis was a natural result of aging, like gray hair and wrinkles. This is now being challenged. A study on a tribe of Mabaan Africans in the Sudan showed very little hearing loss due to presbycusis. Africans at the age of sixty had as good or better hearing than the average North American at the age of twenty-five. Dr. Samuel Rosen, a New York otologist under whose supervision the study was made, attributed the superior hearing ability of the Africans to their noise-free environment. The loudest sounds the Mabaan heard were the sounds of their own voices singing and shouting at tribal dances.
How Fast Is the Ambient Noise Level Rising? In chapter Five we saw how the noises of technology rubbed their way into both urban and rural life and how they were sanctioned as “progressive.” By 1913 Luigi Russolo was able to point out that the new sensibility of man depended on his appetite for noise. Today, as the machines whirl in the hearts of our cities day and night, destroying, erecting, destroying, the significant battleground of the modern world
has become the neighborhood Blitzkrieg. It is another reminder of the truth of Constantin Dox-iadis’s statement that for the first time in history we are less safe inside the city gates than outside them.
Precisely how fast the ambient noise level of the modern city is rising has been difficult to estimate. The figure of one decibel per year has frequently been given, but this seems excessively high when we remember that the decibel is a logarithmic term, so that a mere three decibels is approximately equal to a doubling of sound energy. In recent years, a great number of acoustical engineering surveys have been carried out in various cities in an attempt to determine the present noise level. It is an expensive proposition to do this properly, for thousands of readings must be taken by skilled workers using expensive equipment.
In order to point up the shortcomings of such surveys I will mention only one, though it is typical of them all. In 1971 Vancouver commissioned an extensive survey in which some ten thousand readings were taken over a grid stretching across the whole city region. The report concluded (in almost the only paragraph intelligible to the general public): “Traffic noise is the most significant noise source at all times. During the day hours local traffic noise was found to be responsible for 40% of all noise sources while distant traffic constituted some 13%. At night the corresponding values were 30% and 26%.” Comparing their findings to those of similar surveys conducted elsewhere, the researchers concluded that the noise in Vancouver was some 6 to 11 dBA worse than that of some American cities in 1954. That would be an increase of about half a decibel per year. But this is not particularly meaningful comparison, and the survey will only become useful if it is repeated in Vancouver in an identical manner at some later date. Given the rapid refinements of technical measuring, however, it is doubtful whether this will ever happen. Even then, without an integrating social survey to discover what the public thinks about the changing soundscape, the value of any engineering survey will remain under suspicion.
When a simple solution to a problem exists, an administrator will usually prefer a gummy one. I have already suggested that a simpler way to calculate the ambient noise increase would be to measure the sound signals of the community. The assumption would be that the level of ambient noise would rise in proportion to social signals, which must always remain above it. We did this for Vancouver by measuring the sound levels of different fire engine sirens, beginning with a 1912 La France device (88-96 dBA) and concluding with the newest 1974 siren (114 dBA), all measured at a distance of 3½ to 5 meters. This showed that the signals of emergency vehicles had risen some 20 to 25 decibels in sixty years, or nearly half a decibel per year on the average. The study complements and extends that of our acoustical engineering colleagues quite nicely, and extends our knowledge half a decade into the past. But, alas, few bellies were fed in the process.w
Public Reaction to the Rise in Ambient Noise If the ambient noise of the modern city is rising by something like half a decibel per year, what does the public think of it? One of the questions we asked municipal officials around the world was to list the noises receiving the most complaints from the public. The table below shows the total number of times each source was mentioned in each general category.
TYPE OF NOISE NUMBER OF TIMES MENTIONED
Traffic (general) 115
Construction 61
Industry 40
Radios/Amplified music 29
Aircraft, etc. 28
Motorcycles/Motorbikes, etc. 23
Trucks 21
Animals 20
Bands/Discotheques 12
Parties 9
Power lawnmowers 7
Neighbors/People 7
Railroads 6
Shipyards 4
Snowplows 3
Snowmobiles 3
Church bells 2
Other 19
It will be more interesting to see how the complaints vary according to area. From numerous officials we obtained detailed reports on the number of complaints received for various categories of sound nuisance. Although the categories employed differ considerably, by reproducing the figures from six different cities on three continents some conspicuous differences can be observed.
London (England) 1969
Chicago (U.S.A.) 1971
TYPE OF NOISE NUMBER OF COMPLAINTS TYPE OF NOISE NUMBER OF COMPLAINTS
Traffic 492 Air-conditioners 190
Building sites 224 Construction 151
Telephones 200 Refuse trucks, etc. 142
Office machinery, etc. 180 Other trucks 125
Refuse vans 139 Factory noise 113
Street repairs 122 Musical instruments 109
Trucks (lorries) 109 Exhaust fans 97
Sirens 86 Loudspeakers 95
Ventilation machinery 69 Motorcycles 82
Voices 59 Automobiles 80
Motorcycles 52 Horns 77
Aircraft 42 Vibrations 55
Doors 34 Gas stations 34
Radios 10 Church bells 25
Railways 9 Trains 23
Factory machines 5 Miscellaneous 214
Miscellaneous 81
Source: Report of the Quiet City Campaign, Port and City of London Health Committee, Guildhall, London, 1969. Source: Department of Environmental Control, Chicago, Illinois.
Johannesburg (South Africa) 1972
Vancouver (Canada) 1969
TYPE OF NOISE NUMBER OF COMPLAINTS TYPE OF NOISE NUMBER OF COMPLAINTS
Animals and birds 322 Trucks 312
Amplifiers/Radios 37 Motorcycles 298
Construction 36 Amplified music/Radios 230
People 34 Horns and whistles 186
Machinery, etc. 29 Power saws 184
Home workshop 25 Power lawnmowers 175
Air-conditioning/Refrigeration 19 Sirens 174
Animals 155
Traffic 18 Construction 151
Musical instruments/Bands 15 Automobiles 138
Sirens 9 Jet aircraft 136
Milk deliveries 5 Small aircraft 130
Mowers 2 Industrial 120
Busses 1 Hovercraft 120
Refuse collection 1 Domestic 95
Vendors 1 Foghorns 88
Trains 86
Children 86
Office noises 81
Source: Noise Control Division, Medical Health Department, City of Johannesburg. Source: A Social Survey on Noise, World Soundscape Project, Simon Fraser University, Burnaby, B.C., Canada.
* * *
Paris (France) 1972
Munich (German}/) 1972
TYPE OF NOISE NUMBER OF COMPLAINTS TYPE OF NOISE NUMBER OF COMPLAINTS
Domestic and neighborhood noise
1,599 Noisy restaurants 391
Construction and road works
1,090 Industrial noise 250
Industrial and commercial noise
1,040 Construction 87
Restaurants and cabarets
553 Traffic 29
Miscellaneous
90 Domestic noise 27
Aircraft noise 11
Miscellaneous 2
Source: Bureau de Nuisances, Paris, France. Source: Der Umweltschutzbeauftragte, Landeshauptstadt Mvinchen.
While these statistics have been differently organized, some quite intriguing variations emerge. Note for instance the difference between the chief complaint in London and Chicago; or that between the chief complaint in Johannesburg and Vancouver—two cities of approximately the same population and both in temperate climates. Note also the way the proximity of sea and forest have affected the types of complaint from Vancouver. Also of interest is the varying incidence of traffic noise complaints in the six cities. As the general world survey placed it indisputably at the top of the list of offensive sounds, some explanation is necessary.
Whether a person complains about a sound or decides to bear it may be partly conditioned by whether or not action can be expected as a result f the complaint. This at least was the experience in Chicago. In 1971 a new Chicago ordinance went into effect. It
is one of the toughest and most comprehensive anywhere in the world. The immediate reaction to the new law was a dramatic increase in the number of complaints. In 1970 the city government received approximately 120 noise complaints. During the first six months of 1971 (before the new law went into effect) the number rose to approximately 220; but during the latter half of the year it soared to 1,300, and has been steadily climbing ever since.
Increase of noise complaints in the city of Chicago.
Some Aspects of Noise Legislation The only truly effective piece of noise legislation ever devised was in the form of divine punishment. In The Epic of Gilgamesh (c. 3000 B.C.) we read:
In those days the world teemed, the people multiplied, the world bellowed like a wild bull, and the great god was aroused by the clamour. Enlil heard the clamour and he said to the gods in council, “The uproar of mankind is intolerable and sleep is no longer possible by reason of the babel.” So the gods in their hearts were moved to let loose the deluge.
The first example of a by-law in the modern sense relating to noise was passed by Julius Caesar in his Senatus Consultum of 44 B.C. “Henceforward, no wheeled vehicles whatsover will be allowed within the precincts of the city, from sunrise until the hour before dusk. … Those which shall have entered during the night, and are still within the city at dawn, must halt and stand empty until the appointed hour.” Due to crowding in he narrow streets, wagons were permitted to circulate only at night, which can hardly have assisted sleep. In his third Satire, Juvenal (AD. 117) says: “It is absolutely impossible to sleep anywhere in the city. The perpetual traffic of wagons in the surrounding streets … is sufficient to wake the dead.”
The Soundscape: Our Sonic Environment And The Tuning Of The World Page 23