How much does hearing protection reduce noise?

The amount of noise that hearing protection reduces is indicated by its Noise Reduction Rating (NRR), which is measured in decibels (dB). The higher the NRR, the greater the potential for noise reduction. However, the actual noise reduction achieved in practice can be less than the rated reduction for various reasons, including improper fit, incorrect use, or the type of noise. Typically, earplugs can reduce noise by 15-30 dB and earmuffs by 15-25 dB, depending on the fit and quality. When used in combination, they can offer additional protection.