Simon Cowell is done keeping quiet. As America's Got Talent kicks off season 21 on June 2, the judge is revealing what makes this year different.

The trailer teases three Golden Buzzers earned in a single night for the first time ever. One goes to 14-year-old singer Lai Noelle. Cowell tells WCNC Charlotte that he's hoping for acts "we've never seen before or something better than we've seen before." The bar has been raised.

A new Judges' Callback round follows initial auditions, giving selected performers a second chance to impress. Cowell says this changes things. "I got to know them better," he explained, "and I think the audience at home are going to get to know these people way better." Contestants will have more time to tell their stories than a quick introduction.

Sofía Vergara, Melanie "Mel B" Brown, and Howie Mandel join Cowell on the panel, with host Terry Crews steering the show. Contestants don't go straight to the judges' room. They first complete open-call virtual auditions with casting producers, then get vetted by executive producers before facing the four judges.

Cowell's message to fans is straightforward: expect surprises. "I want the show to be better," he said. "I really hope that we find someone who's going to do really well after the show." Season 21 will feature everything from sword-swallowing to robot dancing to aerial acrobatics.

America's Got Talent season 21 premieres at 8 p.m. EST on NBC. For the full breakdown of behind-the-scenes secrets, head to E! Online.