Tested according to ANSI Space S3.19-1974
The level of noise entering a person's ear, when hearing protector is worn as directed, is closely approximated by the difference between the A-weighted environmental noise level and the NRR.
Easy Instructions
Ear plugs must be inserted properly for optimum performance.
Practice of insertion is recommended. Please refer to the video fitting instructions at Hearos.com. Discard product after several uses or as soon as dirt or wax accumulates on ear plugs.
Attenuation Chart (ANSI S3.19-1974) | |||||||||
Frequency | 125 | 250 | 500 | 1000 | 2000 | 3150 | 4000 | 6300 | 8000 |
Mean Attenuation (dB) | 36.1 | 37.4 | 39.7 | 38.6 | 38.5 | 44.6 | 45.4 | 47.4 | 48 |
Standard Deviation (dB) | 3.6 | 4.9 | 4.3 | 3.1 | 2.7 | 3.2 | 4.1 | 3.2 | 3.2 |
Example:
The range of noise reduction ratings for existing hearing protectors is approximately 0 to 30 (higher numbers denote greater effectiveness)