'X Factor' Mystery: What's That in Britney Spears' Ear?

Ray Mickshaw/FOX.

Viewers of Fox's The X Factor might have noticed judge Britney Spears wearing an accessory on her right ear for the season’s first live episodes -- and we’re not talking about the sparkly kind.

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To the trained eye, it seemed the pop star had an in-ear IFB (interruptible feedback), which allows a producer or the control room to communicate directly, possibly feeding lines or direction. Or so an on-set source tells The Hollywood Reporter. But Spears’ manager Larry Rudolph insists it’s a custom-molded earplug aimed at noise reduction. 

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A show rep confirms it’s to deaden the sound: “Britney wears it for the crowd noise. It’s absolutely not an IFB.” Indeed, another insider says that Spears "seems to have sensitivity to loud sounds," pointing out that she would often cover her ears during the audition rounds when the crowd got particularly unruly. 

As for why fellow X Factor judges Simon Cowell, L.A. Reid and Demi Lovato are plug-free, Cowell’s rep says it’s “just personal choice -- same as the crew. Some choose to use them, and some don’t.” Still, if Spears is volume-averse, why was she wearing a plug in only one ear? Rudolph says she lost the left earpiece -- but assures she’ll be sporting both on future shows.

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And according to the singer, there should be plenty more shows on the horizon. Spears said at Monday night's X Factor Top 12 party that she will "definitely" be back for season three. 

X Factor airs tonight at 8 on Fox. 

Twitter: @shirleyhalperin