HML values

The HML values indicate for hearing protection how high the sound insulation is in relation to three frequency ranges (H (igh) for high, M (edium) for medium, L (ow) for low).

H (High) defines the frequency range between 2000 and 8000 Hz, M (Middle) between 1000 and 2000 Hz, L (Low) between 63 and 1000 Hz.

Example of attenuation values for earmuffs in accordance with the EN 352-1 standard: H 27 dB, M 22 dB, L 15 dB.