For Riot, you really need work on the stage the noise is really annoying for the player.
First : Booing is okay
Nah bro, its really one sided to attack the other team's mentality and we can say that's not fair
Second: They Crowds's cheer or what ever
Really effect the game play that really base on sounds, you think its fair?, i give you an example: Drx v Loud, Map: Split
When aspas and the other i dunno who flanking on ramen, they know exactly the timing when the drx player cross to B Main. How? the crowd help them by whoooooooo
So what you need to works to fix all of these riot?, just build sound proof glass in the middle of the stage, take example like TI Dota