The Noise Reduction Rating (NRR) is a single number that indicates how much a hearing protection device, like earplugs or earmuffs, can reduce noise exposure, measured in decibels (dB). A higher NRR indicates a greater reduction in noise exposure, meaning the device is more effective at protecting your hearing.
It’s important to note that the NRR is a laboratory value and often overestimates real-world performance. To estimate a more realistic real-world noise reduction (NRR) value, you can subtract 7 dB from the NRR and then divide the result by 2, which is often referred to as "derating" the NRR. This adjustment accounts for factors like improper fit and variations in how hearing protection devices are used in real-world settings, which can affect their performance.
The Noise Reduction Rating (NRR) of hearing protection devices in the USA typically ranges from 0 to 33 decibels (dB), with higher values indicating greater noise reduction. Most hearing protection devices fall within the range of 20 to 30 dB. Some devices, like custom molded earplugs or double protection (earplugs and earmuffs combined), can offer even higher levels of protection, potentially reaching 36 dB or more, but these are less common.
