NRC, or Noise Reduction Coefficient, is a metric used to quantify the sound absorption capabilities of an acoustic product. Ratings range from 0 to 1: an NRC of 0 implies no sound absorption, while an NRC of 1 signifies complete absorption. Simply put, higher NRC values indicate sound absorption.

The thickness and density of a product are key factors in determining its NRC rating. For instance, an acoustic product with a rating of 0.95 means it absorbs 95% of the sound in the space, with the remaining 5% being reflected.