The sound equivalence level (SEL) represents the cumulative power of noise in a 1 s period and is also an important measure of exposure, including for effects on sleep.Intermittent and impulsive noise is also impactful on health. The L dn is a measure of cumulative noise exposure over a 24 hour period with a penalty for sound at night.

The L eq(1hour) measure represents an average noise exposure over a one-hour time period.

Measures of noise exposure integrate sound power over a period of time. A 10 dB(A) change in noise represents an eightfold increase in power, and corresponds to a doubling of perceived loudness. Noise is measured in terms of its frequency as well as intensity of sound the dB(A) weights sounds in the audible range of humans.īecause noise is measured using a logarithmic scale, a 3 dB(A) change in noise, a level which is generally noticeable, corresponds to a doubling in the power of the generated noise. Sound level (dB) = 20 log 10 (p measured / p ref) The decibel is a widely used unit of sound measurement and represents a logarithmic ratio of the power of the sound relative to the power at the threshold of human hearing. Health protective laws, attention to design and planning, and improvements to machines can minimize noise from transportation, construction, mechanical equipment, entertainment, and human behavior. While there has been progress in limiting noise along airport flight paths, relative to other environmental problems, such as air pollution, there has been limited progress on noise management over the past several decades. Many cities and states have laws that limit noise in residential areas however, these laws are variably enforced. While urban noise may seem inevitable and unavoidable, even the most dense and active places can take steps to limit noise. Long term exposure to noise from road, rail, and air traffic results in physiological and psychological stress, which indirectly may contribute to heart disease, and high blood pressure.Ĭhronic or repeated exposure to sounds at or above 85 decibels can cause hearing loss. The long-term consequences of these effects on children ‘s development are particularly significant. Noise interferes with cognitive functions, including attention, concentration, memory, reading ability, and sound discrimination. Insufficient or poor quality sleeps results in stress, fatigue, and changes in body’s chemical balances. Noise not only makes hearing, concentrating, and working more difficult,

Urban noise affects more than quality of life issue the level of noise in many cities can cause serious and long-term harm to health, Still, noise is a leading source of dissatisfaction for city residents. With active populations, road traffic, industry, and construction, cities are expectedly noisy places. The sounds we hear become noise when they are unwanted-when sounds interferes with thinking, concentrating, working, talking, listening, or sleeping. But, it is a sense that human’s can’t turn on and off voluntarily. Hearing evolved to alert humans to changes in their environments.

Methods of controlling noise pollution