Acoustic Terms and Definitions: Noise Control Products
Noise Control Products are products that reduce the sound pressure level (also referred to as “NOISE”) by absorbing sound energy. Sound absorption materials do not reflect sound waves m but rather absorb them as a sponge. Good example of sound absorption material is Acoustic blanket Producer’s choice. As sound reaches the blanket it is not reflected, but instead goes through the blanket and spends its energy on vibrating the fibers of inside the blanket. The energy is converted into small amounts of heat. Sound Absorption products have to be porous so the sound can get in, such as foam, fibers, porous stone etc.
Noise Control Products are used to cancel sound reflections and echo. Efficiency of different materials at sound absorption is measured by using a single value number, known as NRC = Noise reduction coefficient. NRC 1.0 means 100% sound absorption. NRC 0.8 means 80% Sound absorption.