How Integral Is Sound?

I'm wondering here but when it comes to the game itself what do you all think about the importance of sound?

I'm talking about sound effects, not the music, but the actual in-game sound effects.

Personally I find that it's important, that there is a lot of "Feedback" you get from the game. Whether it be Rammus powerball's distinctive whirring, the noise of Sion ulting, or even the sound effect of a flash poofing every tid bit of info tells you something that you might not have seen.

However I often feel that the game is a bit lacking, that there are times when I wish I could hear a bit more. something I'm wondering is if you can HEAR things in the fog of war? Obviously you can't see it, but lets say I'm at the mid tower and I'm next to the raptor camp. It's dark, but someone on the other side is killing it. Can you hear them fighting the raptors? Cause if not I think it'd be great if you could...