Why Do Some People ‘Talk in Their Sleep’ and What Does It Mean?

Some people talk in their sleep because their brain is still working even when they’re asleep. During the night, there are different stages of sleep, like when you're dreaming or deep sleeping. When someone talks in their sleep, it usually happens during a lighter stage of sleep, called REM sleep, where dreams happen. The brain sends signals to the mouth and throat to make sounds, which is why they talk out loud without being aware of it.