*SNR or Single Number Rating is the EU's standard for representing the attenuation of hearing protection. Like the NRR, or Noise Reduction Rating, used in North America, the SNR gives the user a rough estimate of the attenuation offered by the hearing protection device in question. While the two ratings are similar, the procedure in which these ratings are achieved differs. There is no exact formula for conversion of SNR to NRR but SNR products tend to be rated roughly 3dB higher than their NRR rated counterparts.
