Sleep talking is a sleep disorder known as somniloquy. For people who sleep talk, they are typically not aware of the experience and will not recall it the next day.
If you’re a sleep talker, you may talk in full sentences, speak gibberish, or talk in a voice or language different from what you’d use while awake. Sleep talking appears to be harmless, but it may increase in frequency when the person is stressed or anxious [1]. The clinician will ask about abnormal movements and behaviour (e.g., sleepwalking, REM sleep behaviour disorder) that may accompany sleep.
Sleep talking can occur in different stages of sleep [2].
Stages 1 and 2: In these stages, the sleep talker is not in as deep of a sleep as stages 3 and 4, and their speech is easier to understand. A sleep talker in stages 1 or 2 can have entire conversations that make sense.
Stages 3 and 4: The sleep talker is in a deeper sleep, and their speech is usually harder to understand. It may sound like moans or gibberish.
There is no scientific evidence to indicate that people who sleep talk are more honest. It is quite challenging to study this relationship as many people utter nonsense in their sleep.
References:
1. Sleep Talking | National Sleep Foundation. Sleepfoundation.org. Published 2019. Accessed December 13, 2019.
2. Pevernagie DA, Boon PA, Mariman AN, Verhaeghen DB, Pauwels RA. Vocalization during episodes of prolonged expiration: a parasomnia related to REM sleep. Sleep Medicine. 2001;2(1):19-30. doi:10.1016/s1389-9457(00)00039-3
