Quiet please! Fighting noise pollution
Key text
This topic is sponsored by the bequest of J S Anderson, FAA.
Increases in the density of residential and commercial buildings, more traffic on the roads, and out-dated building regulations are all contributing to serious noise pollution in our cities.
Noise is an inescapable part of modern life. Traffic on the road, low-flying aircraft, dogs barking, lawn mowers, and music blaring from ghetto blasters are some of the noises polluting our cities.
Judging by the number of complaints made to authorities, Australians are becoming increasingly irritated by urban noise. In Sydney there are over 100,000 noise complaints a year, most of which relate to noisy neighbours.
Similarly, in one of Melbourne’s inner city councils, complaints about noise more than doubled in 2000 after higher density housing was permitted. Even in thinly populated Tasmania, approximately half the environmental complaints relate to noise.
But it is not just the number of complaints that is on the rise. There has also been a sharp increase in noise litigation, with people prepared to take legal action to protect their peace and quiet. Of even greater concern is the effect excessive noise can have on the physical and psychological well-being of people (Box 1: Health issues related to noise pollution).
Sounds of the city
Noise pollution can be defined as any unwanted or offensive sounds that unreasonably intrude into and disturb our daily lives (Box 2: What is noise?). Noise originates in all sorts of ways, but, in general, increasing noise pollution is primarily the result of the increasing population of cities. More people mean more road, rail and air traffic, more industrial noise, and more neighbourhood and recreational noise.
A contributing factor to the rise of noise pollution is the increase in high- to medium-density housing. People are leaving the traditional quarter-acre block in the suburbs and moving into apartments, town houses and converted warehouses in the central and inner city areas. Australians are now living and working physically closer to each other than ever before.
And people are noisier now than they were a generation ago. Most homes now boast at least one television, one radio, a thumping stereo system and a range of noisy household appliances.
Controlling noise pollution
There is no single government authority in Australia with overall responsibility for controlling or reducing noise pollution. The Commonwealth government takes responsibility in areas such as aircraft noise (Box 3: Planning to reduce airport noise) and emission standards for new motor vehicles (Box 4: Traffic noise – sources and solutions), while an environment protection agency regulates environmental noise in each State. The National Occupational Health and Safety Commission has a national code of practice that provides advice on management of noise in the workplace. Neighbourhood and recreational noise issues are usually the domain of the police and local councils.
Guidelines for the sound insulation and acoustic properties of walls between adjoining units in multi-residential buildings are set out in the Building Code of Australia (BCA). The number of complaints from unit owners indicates that these guidelines are too lenient, and moves are underway to improve the building code. Currently the Australian Building Codes Board, which administers the BCA, is considering strengthening the present sound insulation provisions in the code. This will lead to a rationalisation of the present tangle of different standards and set new regulations that can be easily understood and applied by the building industry (Box 5: Soundproofing noisy buildings).
Sound design
While tougher regulations are one way to combat noise pollution, smarter urban planning and improved building design will also help to create a quieter environment. Steps that can be taken include:
- using dead-end streets and car-free malls as sites for residential complexes;
- depressing freeways and arterial roads below the level of adjoining residential areas;
- creating the maximum separation between roads and new buildings;
- siting high-rise buildings at the front of a development, thus providing acoustic shielding for any low-rise buildings behind them; and
- using natural topographic features to the best acoustic advantage.
Careful design within a building can also reduce the effects of noise pollution. For example, if the front of a building is exposed to traffic noise, it makes sense to locate bedrooms at the rear. A garage between the house and the street provides an additional noise barrier.
Quiet buildings
Noise inside a building can be reduced if both the external and internal walls have high sound reduction. Heavy, dense materials such as masonry or brick walls are better for sound reduction, but there are also lightweight solutions. For example, interior walls that have layers of plasterboard with sound-control material in the cavity can be very effective in reducing noise.
Windows and doors are often the weakest link in sound insulation. Double glazing is particularly effective for windows, especially if the airspace between the two panes is as wide as possible. Solid-core doors are best, particularly for those that open on to external areas. All gaps and openings around both doors and windows should be well sealed – even the smallest openings can leak significant amounts of noise.
Sound versus noise
Sound is an important part of everyday life: for communication, for enjoyment or for alerting us to danger. But when sound becomes noise, we like to know there are regulations protecting us from its harmful effects.
Boxes
1. Health issues related to noise pollution
2. What is noise?
3. Planning to reduce airport noise
4. Traffic noise – sources and solutions
5. Soundproofing noisy buildings
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Posted June 2002.