I've posted this before, but I imagine its been lost in the shuffle..
While hunting with a buddy, we spot 3 dogs out there about 1000 yards (yep-no typo 1000). We pull the truck over, get out and belly crawl about 400 yards, then I range with my Leica two dogs laying down at 700 yards, and one closer at 600 yards.
The wind was blowing a bit, about 7 mph, from our left, no sun-it was overcast with no fog.
We were in full snow camo, sitting in a bit of high grass that stuck out of the snow, on a tiny rise, and for the heck of it, I told my hunting buddy to "squeak" with his mouse squeaker.
When he did, all three looked up-Instantly.
Mind you, I don't mean he squeaked a couple of times...He did it just ONCE.
If this doesn't answer your question....nothing will.