Explaining NRC: Noise Reduction Coefficient


What is NRC coefficient? Did you know: NRC stands for noise reduction coefficient and is the standard rating for how well a material absorbs sound?

Typically, the NRC rating of a material is viewed as a percentage. For example, an NRC rating of .75 means 75% of the sound energy coming in contact with that specific material is absorbed. Simple put: the sound is not reflected back into the room to create noise. This material can also be considered 25% reflective.

Although NRC is often thought of as a figure used for rating acoustic products, in reality, every material around us has an impact on acoustics and can be tested for a rating.

The NRC figure ranges from 0.00—perfectly reflective—to 1.00—perfectly absorptive. NRC is always expressed as a decimal that is rounded to the nearest 0.05. For example, an unpainted brick that absorbs very little sound may have a rating of .05 while 1-inch-thick cork wall tiles may be extremely absorptive, with a rating of .70.

So, what does this mean to you? A loud, reverberant room will need additional sound absorption. Materials with a rating of .75 or higher are generally considered to be highly absorptive and will bring about the best results; this includes cork, fiberglass, stone wool and sprayed cellulose fibers.

Everyday carpeting and drapes are often thought to be good for sound absorption, but, surprisingly enough, most have a rating of .35 or less! Typically, these materials absorb high frequencies, leaving middle and low frequencies unaffected.

At Residential Acoustics, we pride ourselves on helping you reduce the sound in your bedroom, living room and office with quality, state-of-the-art products such as the AcousticCurtain™ and AcoustiDoor™! These soundproofing products can instantly eliminate noise.

To ensure you get the absolute best results, call TODAY for a FREE over-the-phone consultation! One of our soundproofing experts will assist you in diagnosing your issues and offer a solution—the best approach to fix them.