Doesn’t seem like much more of an advantage than people yelling things at baseball players?
Seems like it could just be part of the calculation of the competition rather than working so hard to avoid it.
Baseball isn't a game of hidden knowledge. The audience mood can give away details about the other team.
Think poker. If another player bluffed and the audience gasps, you know something notable happened.
For instance, if certain characters from one team are not showing on the map for the opponents and they suddenly hear a crowd yelling, they could anticipate that the character is about to do a surprise gank, attempt to solo Roshan, etc, and shut down the attempt more easily.
It can be heavily bias the decisions that players might make under certain circumstances, so it makes sense that Valve would go to great lengths to prevent that.
Usually when a player is walking up to a hidden enemy the crowd changes in a noticeable way, even on the stream. It's not an individual shout so much as the overall noise.
If a caster yells out "they're smoking" and the entire audience hushes in anticipation then one team knows that the other is trying to make a play and can either group up or avoid the fight.
The International is a tournament where the prevailing team wins millions and millions of dollars. Sound isolation is really important to provide an even playing field.
The baseball equivalent would be the crowd knowing signals between the pitchers and catcher and yell them out so the batter always know what pitch is coming. (this is pretty much the only hidden information in baseball)
That would pretty much ruin the game (in some players/fans mind at least). And in fact this is something the MLB is actively trying to solve by providing encrypted signal communication devices so players don't have to rely on finger/etc signals that can be decrypted by the opposing team.
- the crowd whistling to tell their favourite team that the enemy team is making some kind of secret play (e.g. taking Roshan, or using a smoke).
- clearly hearing the play-by-play commentary that's being played to the crowd over the arena's loudspeakers, which can also give away information about what the enemy team's doing.