About how far will these gunshots be heard?

how the altitude and temperature plays into the sound, not sure, lol but i live out in the stix where we all [ me and my neighbors ] shoot guns allot for target practice, and i can hear gunshots from about 2 miles away if is a rifle and it sounds like it could be fireworks or a random noise at that far away. With shotguns i don't think they can hear farther than 500 yards away. Just my experience.