Sensory deprivation means that most or all of your senses are blocked from getting information. It can happen when you wear special goggles that block out light, or when you put on ear plugs and lay in a tank with no sound. Without this info from your senses, like sounds, smells, or sights, your brain can start to create its own images or sounds and make you feel relaxed. It helps some people to calm down and clear their mind.