ANSI S3.19: 1974

ANSI S3.19: 1974

Ensure the hearing protection provides a predictable level of protection

ANSI S3.19-1974 covers the technique for calculating Noise Reduction Rating (NRR), a noise reduction factor, in decibels, that takes into account performance variation of protectors in their effectiveness in reducing noise, due to differing noise spectra, fit variability, and the mean attenuation of test stimuli at the one-third octave band test frequencies. ​

Testing method:

10 human subjects are used for hearing protector evaluations with 9 test frequencies.