What Does NRC Rating Mean? | Overtone Acoustics
In the glossary of acoustical terms, you may come across the acronym “NRC.” An NRC rating, or Noise Reduction Coefficient, is the average rating that quantifies the degree to which an acoustic panel absorbs sound. Put another way, an NRC rating determines how much quieter a sound panel can make a given room. NRC is used in a variety of applications, with typical examples including the rating of acoustic wall panels, ceiling tiles, office screens, banners, and other similar objects.
What The Ratings Mean
To take it a level deeper, the NRC is a scalar representation of how much sonic energy is absorbed when it strikes a specific surface. A Noise Reduction Coefficient rating of 0 means there is perfect reflection on a particular surface, whereas an NRC of 1.0 indicates perfect absorption. So if you have an NRC rating of .5, that means 50% of the sound has been absorbed while 50% has been reflected. Two of the most important factors that affect an acoustic panel’s NRC rating are the thickness and density of a particular panel.
For reference, a wall made of drywall that has been painted has an NRC of about .05, meaning it absorbs a meager 5% of the total sound while reflecting 95%. A heavy, dense carpeted floor, on the other hand, might have an NRC in the range of .30. At Overtone Acoustics, our acoustic wall panels are composed of a high-density fiber core which effectively controls primary and flutter echo. Our sound absorption panels have an NRC in the range of .80, which offers exceptional absorption while maintaining the organic energy of a room — it’s important to keep some reverberation and natural echo in a room to make sure it doesn’t become overly “dead.”