This usually occurs in REM sleep, when dream states occur. It is not necessarily pathological.
the person who talks in ones sleep is a Somniloquy.
A somniloguist is a person who talks in their sleep. This can occur during different stages of sleep and may not always be coherent or understandable.
Sometimes a person is more interesting when they talk in their sleep. This may be the only time to have an intelligent conversation.
He talks about his day in his sleep.
somniloquy
what do you call a person who talks very less
* Unless you are in the same room as they are then you will never know if they talk about you in their sleep.
Catch him while he talks in his sleep :-)
of course dump him NOW!!!!
A person who talks out of turn can be called disruptive, inconsiderate, or impulsive.
A blabberer is a person who blabbers, who talks incoherently.
A person who talks nonsense can be called an eccentric, a babbling fool, or a gibberish speaker.