We've already discovered that Christina Aguilera is pretty good at celebrity impressions - especially those of her old pop rival, Britney.

The singer sang nursery rhyme Little Miss Piggy in Britney's signature rasp to the tune of Baby One More Time when she was a guest on the Jimmy Fallon show in February.

But on a promotional teaser for the US version of The Voice, the Dirrty hitmaker outdid herself when she impersonated Miley Cyrus, Britney Spears, Sia, Lady Gaga, Shakira and Cher.

She poked fun at Britney's ditzy personality in the skit, brandished a foam finger and flirted with the stage crew as Miley Cyrus and mocked her friend and Burlesque co-star Cher, who has a long-held reputation as a diva in the media.

Ms Aguilera, 34, returns to the series as one of the original coaches after being off for the seventh and eighth seasons while she had her baby - joining Pharrell Williams, country singer Blake Shelton and Maroon 5 frontman Adam Levine on the judging panel.