Sound and other acoustic vibrations
Acoustic vibrations are mechanical vibrations (molecular vibrations) that move in a medium, such as air, water or solid materials. It is called sound when the acoustic vibrations are audible, meaning they have a frequency between 20 Hz and 16 kHz. Acoustic vibrations with a frequency lower than 20 Hz are called infrasound, and they are called ultrasound when the frequency is above 16 kHz. In contrast with electromagnetic waves, sound waves need a propagation medium – such as air, water of solid materials.
When the sound is considered unpleasant, one calls it noise. The negative influence of sound on people depends on the level of the sound pressure and the properties such as sharpness, tonality and information content. Subjective factors can also play a role in the negative appreciation of sound.
Noise or noise pollution is one of the main threats to quality of life for densely populated, industrialised countries like Belgium. The main causes of this nuisance are traffic, transport, industry and other activities. The sound emissions of noisy products contribute to noise pollution: outdoor equipment, pleasure craft, household appliances, and music systems.
The sources of infrasound in the living environment are transport vehicles, cooling and heating equipment, household appliances. Ultrasound is often used against rodents, birds and dogs or within the framework of public safety (“Mosquito”-type equipment). Considering that infrasound and ultrasound are barely audible, they also create less annoyance. There can, however, be physical symptoms, including pain, nausea, and pressure in the ears (non-specific symptoms).
In this section you will find information on the different authorities competent for the restriction of noise pollution. At federal level, our FPS is competent for the regulation of noise levels of machines destined for outdoor use.
Federal Public Service (FPS) Health, Food Chain Safety and Environment
Eurostation II
Place Victor Horta, 40 box 10
1060 Brussels
Belgium
Contact Center: +32 (0)2 524.97.97
Published on 26/04/2011 – Page last updated on 26/04/2011