The research: Psychologist and professor Richard Wiseman developed Dream:ON—an iPhone app that plays a carefully crafted soundscape like “beach” or “nature” while you sleep to conjure pleasant dreams. But these soundscapes don’t help you fall asleep like other soundscape apps. Dream:ON monitors your sleep to start the sounds when you start dreaming. And after looking at millions of dream reports, Wiseman discovered the sounds really did guide users’ dreams toward a more pleasant place. What it means: A bad dream does more than keep you up at night. “Bad dreams are like any other form of traumatic experience,” explains Wiseman. “And since the last dream of the night dictates our mood in the morning, they linger in our minds as we replay them again, trying to work out the issue.” Bottom line: Bad dreams can affect your well-being and mental health all day. This research suggests listening to calming soundscapes while you dream can influence the emotional tone of your dreams and help you wake up happy and refreshed. More from Prevention: What Do Your Dreams Mean?