ABSTRACT
Noise rating, noise criterion, preferred noise criterion, room noise criterion, and room criteria curves by and large serve the same purpose, the measurement of acoustic noise. Noise rating curves are a set of curves based on the sensitivity of the ear. They are developed to arrive at a single number (rating) for noise, based on sound levels measured in octave bands. This chapter presents a list of predominantly European requirements and recommendations for noise rating. In general, noise criterion curves are a little flatter in comparison to noise rating curves (i.e., they have slightly lower values at low frequencies and slightly higher values at higher frequencies). The curves were originally defined in octave bands running from 63 Hz to 8 kHz. The room noise criterion curves are designed to describe octave-band sound pressure levels that, when modulated by fluctuations at low frequencies, may cause perceptible vibrations or rattles in lightweight constructions.
