Noise Reduction Rating

{
  "id": "MLC-T-ENV-018726",
  "term": "Noise Reduction Rating",
  "field": "Environment",
  "definition": "1. 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.\n\n2. The noise reduction rating is a single-number attenuation index that represents the overall average noise reduction, in decibels, that a hearing protection device will provide in an environment with a known C-weighted sound level. It is pre-calculated by manufacturers and required by law to be shown on the label of each hearing protector sold in the United States.",
  "abbreviation": "NRR",
  "subject": "Regulatory activities",
  "references": [
    "40 CFR 211.203 (2013 CFR)",
    "EPA Emergency Responder Health and Safety Manual - Chapter 7: Physical Stress Management Program"
  ],
  "url": "https://mlchart.com/terminology/environment/noise-reduction-rating/"
}