Historical
ANSI/ASA S12.2-2008
Criteria for Evaluating Room Noise
This Standard provides three primary methods for evaluating room noise: a survey method, an engineering method, and a method for evaluating low-frequency fluctuating noise. Two methods for evaluating room noise—RC (room criterion) and NCB (balanced noise criterion) curves—were the basis of the previous ANSI S12.2-1995 standard, and RC is included briefly for informational purposes in Annex D. All of the methods assume that the measured noise is free of tones.
Acoustical Society of America [asa]