What is Sleep talking?

Somniloquy or sleep-talking is a parasomnia that refers to talking aloud while asleep. It can be quite loud, ranging from simple mumbling sounds to loud shouts and long frequently inarticulate speeches, and can occur many times during a sleep cycle. As with sleepwalking and night terrors, sleeptalking usually occurs during the less-deep delta-wave NREM sleep stages or during temporary arousals therefrom.

It can also occur during the deeper REM sleep stage, at which time it represents what sleep therapists call a motor breakthrough (see sleep paralysis) of dream speech: words spoken in a dream are spoken out loud. Depending on its frequency, this may or may not be considered pathological. All motor functions are typically disabled during REM sleep; thus, motoric, i.e., verbal elaboration of dream content, could be considered an REM behavior disorder (see below).