Measurement of HML
What is the HML method?
Hearing protection devices can only be approved if the noise attenuation they provide has been measured in an authorized laboratory. All ear protectors from OX-ON are approved and the sound reduction values are stated on the device or printed on the packaging.
The attenuation is measured in three frequency categories: High, Medium and Low (also called the HML method). The figures indicate the ear protector's expected noise reduction in decibels (dB).
- H (High) - indicates reduction of high frequency sounds
- M (Medium) - indicates reduction of medium frequency sounds
- L (Low) - indicates reduction of low frequency sounds