The "Beautiful" hitmaker said her four-year-old kids sing backing vocals when she's practicing at home, reported Contactmusic.
"They sing my new song Infinity already, they're already doing the background vocals... So that's a good sign to me!," she said.
Carey, 45, said life with the twins - whose father is the diva's estranged husband Nick Cannon - can be hectic but always fun.
Recalling her difficult pregnancy with the pair, she said, "The pregnancy itself, it was very difficult. I had gestational diabetes, I had preeclampsia, I had all these things you don't even want to know about...