Hemi-Sync® is an audio technology developed by The Monroe Institute. It focuses on manipulation of the brainwave activity. Hemi-Sync® is based on the natural functioning of the brain that encourages coherent brainwave activity. Our brains produce waves or patterns of electrical activity. Different patterns indicate different mental states, such as rest (occipital Alpha), deep sleep (central Delta), meditation (central and frontal Theta), physical activity (wide-spread Beta).