Built-in Voice Chat

I strongly believe that Riot Game's next big step to improving League of Legends should be to work on and introduce a built in voice chat system. This would allow players to have the option to communicate with their team better, not having to make a pre-made team for normals, and only having voice chat with a duo partner if its possible for them. Obviously, there could be some problems like raging, and more liable disturbing behavior, but I really think that this is something Riot can work on and try to introduce. This would be helpful towards the overall gameplay.