Noise could give you away?

[DRG]

The thing about battle zones is they are rarely quiet. Lot's of things going on generally. Things that go BANG for one a few of those tends to degrade your hearing somewhat.

Wind direction plays a big part in how well you hear things like Helos as well. I live near a dragstrip. When the wind is favourable to me I barely hear it. When the wind blows my way or it's still air it almost sounds like it's in my backyard.

So no, you generally wouldn't here that from kilomters away unless conditions were just right

Don