Noise is generally defined as ‘unwanted sound’ and is perceived as a pollutant and an environmental stressor.

There are physical and psychological components to noise: whatever the physical characteristics of a sound may be, it will only become noise when it is unwanted.

Noise can have direct effects on hearing. In particular, exposure to excessive noise in industry may induce hearing loss. However, noise can also have adverse effects on other aspects of health. The links between environmental noise and health range from the annoyance and anxiety caused by noisy neighbours to the interference of aircraft noise in children’s learning.

Environmental noise affects health in a variety of different ways. There is good evidence for problems in the following areas:

• annoyance and quality of life

• sleep disturbance

• cardiovascular disease

• children’s health

There is also more limited evidence of the adverse effects of noise on mental

health.

In Europe, transport (road, rail and air traffic) is the most important source of urban noise. Approximately 30% of the European Union‘s population is exposed to levels of road traffic noise of more than 55 dB(A). Exposure to high noise levels has decreased in some countries due to technological measures, noise barriers and spatial planning. Due to the expected growth in traffic, extra measures will be needed. At current noise levels many people are annoyed and disturbed in their sleep. A small effect on cardiovascular risk is highly plausible.

The Environmental Noise Directive

This directive aims to address the problem of urban noise. It requires local authorities to draw up noise maps by mid 2007 and to draw up noise reduction plans by mid-2008. The implementation of the directive has particular relevance for city and transport planners, and all those working on traffic and urban issues.

It is expected that streets with high traffic volumes will also turn out to be “noise hotspots”. In this way the Environmental Noise Directive is another tool to limit car use in cities.