Noise Reduction

When aiming to reduce the effects of environmental noise on people, you must consider the following aspects:

• Noise sources
• Transmission path
• Types of homes in which people live

Noise at the source is reduced by reducing its sound power level. For the most common source of environmental noise, road traffic, this is done by reducing speed and the number of vehicles, in particular heavy ones. For industrial sources, power levels can be reduced by, for example, adding silencers.

Outdoor noise levels usually decrease with increasing distance from the source because of geometrical spreading of the noise energy over a bigger surface and absorption of the noise by the atmosphere and by the ground. Thus increasing the distance between source and receiver is an effective noise reduction tool. Barriers can also achieve additional reduction of noise levels.

The sound insulation of buildings is the final barrier to the potentially intrud-ing effects of environmental noise.

Most of Brüel & Kjær's environmental applications are made to assist you with surveying noise fields with the intention of reducing noise.