An unidentified source said to be close to the new series revealed the country singer has been ousted because she was unable to survive the series' "rigorous schedule," "Access Hollywood" reported Friday.

"It became apparent in leading up to the premiere of the show that she could not sustain the rigorous schedule," the source said. "She began to have trouble with her vocals, even losing her voice completely at times."

Series Executive Producer Sally Ann Salsano told "Access" Corn's departure has made room for the country music group Third Town, which will take part in the show's premiere.

"During rehearsals for the first episode, producers realized Third Town was better suited for the Top 12 than Charla Corn," Salsano said. "This was a very hard decision for everyone involved in the show but when a show starts with the Top 12, we, as producers, have to do everything in our power to make sure that the Top 12 acts from the nation wide search are truly represented."