Judges are shown during a rehearsal for the second season of 'The Voice'
Judges, seated from left, Blake Shelton, Christina Aguilera, Cee Lo Green and Adam Levine are shown during a rehearsal for the second season of "The Voice," in Los Angeles. A new Facebook application will allow fans of NBC's "The Voice" to vote for their favorite artists through their Facebook profiles, now known as their timelines. (AP Photo/NBC, Lewis Jacobs)
Read the article: NBC's 'The Voice' adds Facebook app for voting