What does HML mean when referring to hearing protection?

Understanding the HML method for estimating noise reduction levels

HML is a method used to estimate the level of protection offered by hearing protection devices across different noise frequency ranges. The abbreviation stands for:

H = High

M = Medium

L = Low

These refer to the amount of sound attenuation (noise reduction) the hearing protector provides at various frequency levels:

H (High): Attenuation at high frequencies (e.g., above 2000 Hz)

M (Medium): Attenuation at mid-range frequencies (e.g., 1000–2000 Hz)

L (Low): Attenuation at low frequencies (e.g., below 1000 Hz)

Manufacturers test and provide these values to help users understand how well a hearing protector performs across different types of noise environments. By knowing the HML values, safety professionals can select the most suitable hearing protection for specific workplace noise conditions.

Key points:

  • HML is a method for evaluating hearing protector performance.
  • It gives separate attenuation values for high, medium, and low frequency noises.
  • H = High frequencies, M = Medium frequencies, L = Low frequencies.
  • It helps determine which hearing protection is most suitable for different noise environments.
  • Values are typically supplied by the manufacturer after testing.

If you need further support, please contact our Technical Support Team using the email: technical@jspsafety.com or contact us via our WhatsApp.


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