A package marked with a noise reduction rating can tempt a simple calculation: subtract the number from the workplace noise level and assume the result is what reaches the ear. That shortcut can misrepresent the protection a person actually receives.
Laboratory ratings describe testing under specified conditions. Real-world attenuation depends on the protector, fit, use and compatibility with other equipment. NIOSH’s hearing-protection guidance warns that the labelled rating often does not reflect an individual worker’s protection.
Fit belongs in the assessment
NIOSH’s 2025 fit-testing recommendation favours individual quantitative fit testing to assess attenuation. This is more informative than assuming that everyone using the same model obtains the same result.
A workplace programme should begin with the noise exposure and the controls available to reduce it. Hearing protection is one part of that programme, not a reason to ignore quieter equipment, maintenance or other appropriate controls.
When reviewing a protector with the safety team, ask:
- What exposure assessment is this selection based on?
- Has this worker been shown the correct fitting method?
- Does the protector remain compatible with glasses, headwear or other required equipment?
- Can essential warnings and communication still be managed safely?
- When will fit and condition be checked again?
Earplug size and insertion matter. Earmuff seals can be affected by objects between the cushion and skin. A comfortable-looking product may still be poorly fitted, while a product that is uncomfortable may be removed during the very periods when it is needed.
Do not assume that combining plugs and muffs means adding their two package ratings. Selection for high exposures requires an appropriate assessment and programme.
Report damaged cushions, lost plugs or difficulty maintaining the fit. Follow the employer’s instructions for cleaning, replacement and storage rather than keeping worn equipment in use because the printed rating remains visible.
The number on the pack is useful product information. The practical question is whether the chosen protection, correctly worn by this person in this job, provides the required attenuation throughout the exposure.