Noise Reduction Rating

Noise Reduction Rating (NRR). A single number noise reduction factor in decibels, determined by an empirically derived technique which takes into account performance variation of protectors in noise reducing effectiveness due to differing noise spectra, fit variability and the mean attenuation of test stimuli at the one-third octave band test frequencies.

Source

40 CFR § 211.203


Scoping language

None
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