BALLISTIC HEARING PROTECTION (BHP)
All deployed Marines are equipped with Ballistic Hearing Protection (BHP), a two-sided, dual-purpose earplug that protects against steady-state noise and impact noise produced from aircraft, vehicles, machinery, gunfire and explosions. When the yellow side of the earplug is inserted into the ear, the BHP will block loud impulse noise without suppressing critical ambient sounds such as verbal commands. When turned around, so that the green end is inserted into the ear, it provides steady protection against constant, high-level sound sources.
It is protective to 190 decibels (dB), which is greater than the noise of a jet fighter during take-off, with afterburners at a distance of 50 feet (130 dB).