Fire a shot, move head around while firing. Notice the tail stays the same throughout movement. Place soldiers and have them fire. Notice the sound only plays where they are shooting from.
Now run Arma 3 with L_ES (Laxemann's Soundscape Mod)
Repeat the same, but this time notice that when firing your weapon, the tails travel, and you can hear where they go while turning your head. Now when AI are firing, the sound doesn't only come where where they're shooting, but you can hear the tails moving through the landscape.