4.3.3 Pressure Seal Test
Fit Testing Evidence
- There is no correlation between pressure decay and actual acoustic attenuation. A device can pass a pressure test but still provide poor noise reduction.
- Commonly used for custom-moulded earplugs, but the HSE RR727 report showed that many custom moulds that passed pressure tests still failed to provide adequate attenuation.
Pressure Seal Checks
What it is:
Pressure Seal Checks is the integrity of the acoustic seal of a hearing protector by measuring air pressure decay over time. A small probe is used to pressurize the ear canal with the earplug in place, and the rate at which the pressure drops is measured.
Output: Pass/Fail only (no PAR is generated)
There is no correlation between pressure decay and actual acoustic attenuation. A device can pass a pressure test but still provide poor noise reduction.
Commonly used for custom-moulded earplugs, but the HSE RR727 report showed that many custom moulds that passed pressure tests still failed to provide adequate attenuation.
Why it matters: While quick and easy, pressure seal tests should not be relied upon as the sole verification of hearing protection adequacy. They are best used as a quality control check during the manufacturing of custom moulds, not as a substitute for PAR measurement. Related: [#hse-rr727](#hse-rr727).