Noise Reduction Coefficient (NRC)

Noise Reduction Coefficient (NRC) – The arithmetic average, to the nearest multiple of 0.05, of the sound absorption coefficients in the 1/3 octave bands centered at 250 Hz, 500 Hz, 1000 Hz, and 2000 Hz. By convention, the maximum NRC used is 0.95, even though the published laboratory average may be greater.

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