[quote=@Fallenreaper]
<Snipped quote by Dervish>

Even when they have ear comms and helmets to muffle out sounds? *tilts head* This is sci fi too. 

[/quote]

Most soldiers don't have radios or anything like that, and most helmets don't cover your ears. They're basically meant to prevent shrapnel, that's about it. Usually every platoon has a radio or two (varies from unit to unit), and in the case of armoured reconnaissance like I did, it was a radio per vehicle, or 3-4 troops. Keep in mind most soldiers are in a formation most of the time, and under the command of their section commander, so lots of shouting.