ASSASSIN UPDATE PATCH!!!!
The League of Legends PBE (Public Beta Enviroment) is where Riot Games tests upcoming patches/changes/content before publishing to the Live Client. These test that I participate in are recording without Voice Overs in order to get the full audio accosiated with any content/changes.
I would recommend checking out Surrender@20 for tons of information they provide in regards to PBE updates: http://www.surrenderat20.net/