Sleep talk occurs in some people may be due of anxiety, having less sleep, unresolved issues, stress, eating in excess exactly before going to bed. In scientific terms sleep talking is known as SOMNILOQUY.
It is said that why people talk in their sleep can be due to stress in their lives and possibly not having enough sleep. Research has shown that most sleep talking will occur when they go from one stage to another. To find more information … Source:http://answers.ask.com/Health/Other/why_do_people_sleep_talk