Voice Studiois an app that functions for Microsoft testing, much like last year's Xbox LIVE Labs. This time around, they're testing the Kinect's voice recognition, so you'll obviously need a Kinect to use this App. As anyone who has played Halo: Combat Evolved Anniversary, only to say 'hello' to someone thus inexplicably tossing a grenade and killing your co-op buddy in the process can attest to, this needs to be tested, so the more people that get in on this, the better that recognition will be (and the less your co-op buddies will get killed).
You can download Voice Studio from the dashboard. It will ask you to say hundreds of phrases over eight "tracks" and... that's pretty much it. It contains four achievements worth 50G, as well as avatar awards. It appears to only be available from the US Dashboard at the moment, though we'll let you know if it becomes available elsewhere.