The unedited version started going viral Monday, causing track producer William Orbit to release a statement defending the recording.
"I'd like to affirm that ANY singer when first at the mic at the start of a long session can make a multitude of vocalizations in order to get warmed up. Warming up is essential if you're a pro, as it is with a runner doing stretches, and it takes a while to do properly. I've heard all manner of sounds emitted during warm-ups. The point is that it is not supposed to be shared with millions of listeners.
A generous singer will put something down the mic to help the engineer get their systems warmed up and at the right level, maybe whilst having a cup of herb tea and checking through lyrics before the session really kicks off. It's not expected to be a 'take.'"
The song is off Spears' most recent album, Britney Jean, which was released in November 2013.