What are the meanings of NRR and SNR in hearing protection?
SNR: single value noise reduction value detected according to international standard ISO4969-2. It is a standard to evaluate the anti noise performance of hearing protection products by detecting the attenuation degree of HML three frequency noise.
NNR: in accordance with American Standard ANSI S3 Single value noise reduction value detected by 19-1974 standard. It is a standard for measuring the anti noise performance of hearing protection products issued by the American environmental protection organization (EPA) in 1979.
At present, the NRR of anti snoring ear plugs sold on the market is roughly in the range of 0-40db.