Here is the full list of all 10 The Voice achievements worth 1,000 gamerscore. It takes around 2-3 hours to unlock all of the achievements on Xbox One.
You've sung 30 songs
You've won 10 gold medals
You've won 20 medals
You've got a score of more than 90,000 points
You've won The Final of The Voice
You won The Battles Round 2
You've won 5 medals
You passed the Blind Auditions
You've got a score of more than 75,000 points
You made all 4 Coaches turn round at the Blind Auditions