Noise

The environmental effects of man-made noise are distinctly different from other types of pollution, in that they are more localised and affect mainly human beings and other animals. The effects on humans include sleep deprivation, loss of concentration, headaches, irritability and in severe cases partial or full hearing loss. The likelihood of accidents at work also increases if employees are unable to hear shouts or alarms.

In the natural environment, many animals find noise stressful and may abandon their habitat to get away from it. Noise also interferes with communication, for instance a lot of animals and birds use audible signals to find a mate, and if there is excessive background noise they may be unsuccessful.

All engines produce noise, which results from internal friction, sudden changes in pressure and the flow of gases on both the intake and exhaust sides. Ancillary components such as pumps, fans and alternators also make their own contribution.