"We're a little tougher on everybody," the judge told PEOPLE at a Samsung Hope for Children event supporting the Maribel Foundation in Los Angeles. "Because of last season and the standard that we set, it's easy to go, 'Is he as good as even our top 24 from last year?' "
Not to worry, though. Lopez assures there's been no lack of "amazing" voices.
"It's not like you find people just like that, but the ones that we found, we know are very special," she said.
As for how she's getting along with co-judges Steven Tyler and Randy Jackson this time around, Lopez says they're closer than ever.
"They're like my brothers and they drive me crazy like brothers, too," she said with a laugh. "But we love each other, which is why we've become like a family."