Ambient noise is background noise that is always present. The nature and level of this sound can vary considerably, sometimes turning into a distraction or a nuisance. Sound meters are used to establish ambient noise levels for the purpose of researching it and addressing specific complaints about background noise.
This type of noise can take a wide variety of forms. For urban dwellers, for example, it might include cars, horns, construction, trains, aircraft, and voices. In rural regions, the sounds of farm animals, wildlife, wind in the trees, and tractors might be a part of the ambient noise pattern. Controlling this noise is often of interest to people, for a variety of reasons.
In some areas, ambient noise occurs at a very high volume level, becoming intrusive. This is known as noise pollution or environmental noise, and it can have negative health effects, in addition to being obnoxious. Noise pollution is often linked with irregular sleeping patterns, irritation, hearing loss, high blood pressure, and cardiovascular problems. In communities with noise issues, sound monitors may be used on a regular basis to check for high decibel noises, and people can be fined for violating noise ordinances.
Changes in ambient noise patterns can also be of interest or concern. Often, such changes are increases in the noise level. For example, the construction of an airport near a residential community would cause an uptick in noise, and an increase in complaints about it. Concerns about environmental noise have led many communities to put strict procedures in place so that potential increases are considered when discussing applications for construction permits.
A variety of techniques can be used to address noise problems. Trying to keep the noise down is one approach, as is constructing buildings with additional insulation to reduce the amount of ambient noise that gets into homes and businesses. Thick walls, sound baffles, and carpeting can all be used to cut down on noise transmission to make people more comfortable. People may also use white noise machines to drown out other sounds to help them sleep or work.
Some industries have specific concerns about ambient noise. In the recording business, soundproofed recording booths are critical to ensure that background sounds do not interfere with the recording of albums. Some studios even go underground for recording, using earth as insulation to prevent noise from penetrating recording facilities.