Accession Number:



Impulse Assessment of the SureFire(registered trademark) EP7 Sonic Defenders(registered trademark) Ultra Earplug

Descriptive Note:

[Technical Report, Technical Memo]

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The impulse peak insertion loss IPIL is the standard measure of attenuation provided by hearing protection devices HPDs in response to an impulsive noise. This technical memorandum describes the IPIL testing conducted and the calculated mean IPIL values for the SureFireregistered trademark EP7 Sonic Defendersregistered trademark Ultra Earplug. Testing included two test modes cap open i.e., unfiltered and cap closed i.e., filtered. Testing was completed in accordance with the ANSI standard S12.42-2010. All device samples were tested at the nominal levels of 150, 160, and 170 decibel peak dBP, re 20 Pa. A total of five samples were fitted to an acoustic test fixture two times each for a total of 10 trials per test level in both the cap open and cap closed modes. Results of the testing revealed overall higher mean IPIL values when the EP7 earplug was in the closed mode compared to the open mode at all nominal test levels i.e., 150, 160, and 170 dBP. These results suggest that, when properly fit and functional, the EP7 can adequately protect i.e., reduce exposure to less than 140 dBP against impulses below 173.3 dBP in the cap open mode, and 180.0 dBP in the cap closed mode.

Subject Categories:

  • Protective Equipment

Distribution Statement:

[A, Approved For Public Release]