Noise Reduction Rating - NRR 29 Decibels (when used as directed) Smooth Foam for a Soft, Comfortable Fit Information Required By EPA: The level of noise entering a person's ear, when a hearing protector is worn as directed, is closely approximated by the difference between the A-weighted environmental noise level and the NRR. Example: The environmental noise level as measured at the ear is 92 dBA. The NRR is 29 decibels (dB). The level of noise entering the ear is approximately equal to [92 dB[A] - 29] 63 dB(A). The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (Higher numbers denote greater effectiveness).
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