Etymotic ER125-GSP15BN GunSport PRO Electronic EarplugsPassive hearing protection is cheaper, and involves no electronic circuit or batteries. However, it is not selective in its attenuation, lowering both low and high sounds. That results in conversation and other important yet not too loud sounds being drowned and lost. Electronic hearing protection uses a battery powered electronic circuit that samples your surrounding sound levels in real time. Safe sound levels are passed through to your eardrums as