- Background noise
acousticsand specifically in acoustical engineering, background noise is any soundother than the sound being monitored. Background noiseis a form of noise pollutionor interference. Background noise is an important concept in setting noise regulations.
Examples of background noises are environmental noises such as
waves, trafficnoise, alarms, people talking, bioacoustic noise from animals or birds and mechanical noise from devices such as refrigerators or air conditioning, power suppliesor motors.
The prevention or reduction of background noise is important in the field of
active noise control. It is an important consideration with the use of ultrasound(e.g. for medical diagnosis or imaging), sonarand sound reproduction.
astronomy, background noise or cosmic background radiation, is electromagnetic radiationfrom the sky with no discernible source.
information architecture, irrelevant, duplicate or incorrect information may be called background noise.
physicsand telecommunication, background signal noisecan be detrimental or in some cases beneficial. The study of avoiding, reducing or using signal noise is information theory.
* [http://www.acoustics.salford.ac.uk/acoustics_info/concert_hall_acoustics/?content=unwanted_sound How low noise levels are achieved in concert halls]
Wikimedia Foundation. 2010.