What is NRC? NRC stands for Noise Reduction Coefficient and is a standard rating for how well a material absorbs sound.  The NRC rating of a material can be viewed as a percentage.  For example, an NRC of .75 means 75% of the sound energy that contacts that material is absorbed and is not reflected back into a room.  Likewise, this same material can be considered to be only 25% reflective. NRC is often thought to be [...]