InformeDesign: Glossary of Terms

noise reduction coefficient
(NRC)

A number rating that indicates a material’s sound absorbing properties, based on the average absorption for the material over primary speech information frequencies (250 Hz-2000 Hz). The higher the NRC rating the more efficient the material is in absorbing sound. For example, a material with an NRC of 0.70 absorbs approximately 70% of sound energy, while the remaining 30% passes through the material or reflects back into the space.