Sound
Environmental Noise: 92 dBA
Earmuffs/plugs with NRR: 31 dB
Level of noise entering the ear: 61 dBA
NIOSH recommends derating foam earplugs by 50% and earmuffs by 25%. OSHA recommends derating all hearing protectors by 50%. Taking the noise level below 70dB when working near a road could mean you will be less alert to oncoming traffic.Exposure to noise levels above 85dB is considered dangerous to hearing.Although SNR and NRR are applied in the same way, due to testing differences, the SNR rating tends to be higher than the NRR (e.g. a 30dB SNR would be a 25dB NRR). You should take this into account when comparing earmuffs/plugs.
Bibliography
Bibliography
https://www.audicus.com/noise-levels-of-everyday-sounds/https://noiseawareness.org/info-center/common-noise-levels/https://noiseawareness.org/info-center/occupational-noise-facts/https://noiseawareness.org/info-center/noise-music-facts/https://www.hearnet.com/https://noiseawareness.org/info-center/recreational-noise-facts/https://www.cdc.gov/niosh/topics/noise/app.html (NIOSH Sound Level Meter App)
SNR (Signal to Noise Ratio)https://www.workwear.co.uk/blog/signal-to-noise-ratio-what-is-snr.htmlEN 352-1:200
NRR (Noise Reduction Rating)https://noisyworld.org/noise-reduction-rating-usage/ANSI S3.19-1974
NRR (Noise Reduction Rating)https://noisyworld.org/noise-reduction-rating-usage/ANSI S3.19-1974