Buzz was big leading up to Britney Spears' judging debut on Wednesday night's season premiere of "The X Factor," but all that anticipation didn't translate to big ratings.

The premiere didn't just perform below expectations -- the approximately 8.4 million viewers who tuned in made Spears' first appearance the lowest rated episode ever for the American version of "X Factor."

Wednesday's reboot with Spears and Demi Lovato as new judges drew an audience about 25 percent smaller than last fall's premiere episode of the first season of "X Factor."

The lower-than-expected ratings can be attributed to the show's primary competition, NBC singing competition "The Voice." Producers scheduled an extra episode of the show to compete directly with the first hour of the two-hour "X Factor" premiere.

"The Voice" came out on top during that hour, pulling in 10.7 million viewers compared to the 7.5 million who watched "X Factor."

But once "The Voice" went off the air, the "X Factor" audience grew considerably, shooting up by 41 percent in the second half of the show.

With Spears' incredibly huge name recognition and her equally enormous paycheck - a reported $15 million for one season - "X Factor" producers were banking on the "Toxic" hitmaker to draw a large audience, so the number of viewers for Wednesday's episode is likely a disappointment.

Anticipation has also been high among viewers who wanted to see how Spears would fare on live television after she developed an unpredictable and erratic image and a mental illness that affects her personality.  Producers have reportedly banned alcohol of any kind from Spears' hotel and dressing rooms during her work with the show.

Tags: X factor Britney Spears