Technical Bulletin

Page 3
Hearing Protector Guidance
A variety of factors affect the hazardousness of the impulse noises and the degree of hearing protection
required, especially the number of exposures and overall peak level, L
pk
, of each impulse. For example,
the sound made by a weapon fired in an indoor firing range may have a greater intensity due to
reverberation than the same weapon fired at an outdoor range where there is rapid sound decay. The
caliber and type of weapon (handgun versus rifle) can also have a significant effect on L
pk
.
The following guidance is to be considered general in nature since the actual hazard associated with
exposure to gunfire and other impulse noises and the protection obtained when hearing protectors are
worn is influenced by the variables described above.
Regardless of the hearing protector being worn, the user should be alert to his or her own hearing. If
during or after an exposure, tinnitus (ringing or buzzing in the ears) is heard or the user’s hearing seems
muffled or dulled, or for any other reason the user suspects a hearing problem, the fit, condition or
adequacy of the protector should be carefully checked and/or a more protective device or combination
of devices (such as earmuffs and earplugs together) should be worn. For those exposed to weapons
fire on a regular basis, periodic hearing evaluations are advised.
For highest noise reduction: wear dual protection (earmuffs worn over high attenuation earplugs fit
deeply in the ear). This configuration will significantly boost the noise reduction but will reduce the
user’s hearing ability.
For high noise reduction: wear a good quality single hearing protector, such as foam earplugs fit deeply
in the ear or high attenuation earmuffs. This approach may also reduce hearing ability.
For better hearing ability: consider level-dependent hearing protectors, either passive or active.
Possible configurations include the following, with the dual-protection option being the more
protective.
 Single hearing protection
o Electronic level-dependent earplugs such as the 3M™ PELTOR™ Tactical 100, or
o Electronic level-dependent earmuffs such as 3M™ PELTOR™ Tactical Sport, or
o Passive level-dependent earplugs such as the 3M™ Combat Arms™ Earplugs
 Dual hearing protection
o Passive level-dependent earplugs worn together with electronic level-dependent
earmuffs, or
o Electronic level-dependent earplugs worn together with traditional passive earmuffs, or
o Traditional passive earplugs worn together with electronic level-dependent earmuffs, or
o Electronic level-dependent earplugs worn together with electronic level-dependent
earmuffs.
Hunters may choose level-dependent HPDs to balance the need for protection with the ability to detect
and locate nearby game animals. Likewise, target shooters may opt to combine electronic level-
dependent devices with passive HPDs (dual protection) to allow better audibility of range commands
without sacrificing hearing protection.