- Sound baffle
A sound baffle is a construction or device which reduces the strength (level) of
airborne sound. Sound baffles are a fundamental tool of noise mitigation, the practice of minimizing noise pollutionor reverberation. An important type of sound baffle is the noise barrierconstructed along highwaysto reduce sound levels at properties in the vicinity. Sound baffles are also applied to walls and ceilings in building interiors to absorb sound energy and thus lessen reverberation.
Highway noise barriers
The technology for accurate prediction of the effects of
noise barrierdesign using a computer modelto analyze roadway noisehas been available since the early 1970s. The earliest published scientific design of a noise barrier may have occurred in Santa Clara County, Californiain 1970, for a section of the Foothill Expresswayin Los Altos, California. The county used a state-of-the-art computer modelfor predicting the effects of sound propagation from roadways, with variables consisting of vehicle speed, truckmix, roadwaysurface type, roadway geometrics, micro- meteorologyand the design of proposed soundwalls.
Interior sound baffle design
Since the early 1900s scientists have been aware of the utility of certain types of interior coatings or baffles to improve the
acousticsof concert halls, theaters, conference roomsand other spaces where the quality of sound is important. By the mid 1950s Bolt, Beranek and Newmanand a few other U.S. research organizations were developing technology to address the design challenges. This design field draws on several disciplines including acoustical science, computer modeling, architectureand materials science. Sound baffles are also used in speaker cabinetsto absorb energyfrom the pressure created by the speakers thus reducing cabinet resonance. In 1973, Pearl P. Randolph, a school busdriver in Virginia, won a new school bus in a national contest held by Wayne Corporationfor the suggestion that sound baffles be installed in the ceiling of school buses. In 1981, they were first made mandatory by the state of California.
Vehicle exhaust sound baffles
Baffles are also found in the exhaust pipes of vehicles, particularly motorcycles.
Noise health effects
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