Easy Insertion, Forms To Ear Canal ShapeNow Softer for More Comfort Noise Reduction Rating NRR 29  Information required by EPA: The level of noise entering a person's ear, when a hearing protector i sworn as directed, is closely approximated by the difference between the A-weighted environmental noise level and the NRR.   Example: 1) The environmental noise level as measured at the ear is92 dBA.  (2) The NRR is 29 decibels (dB).  (3) The level of noise entering the ear is approximately equal to[92 dB(A) - 29] 63 dB(A). Noise Reduction Rating 29 Decibels (When used as Directed) The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness).