Entrainment is a phenomenon seen is a wide variety of different natural circumstance. In the field of chronobiology, the study of biological rhythms in living organisms, entrainment is the synchronization of a circadian rhythm with the rhythm of an external pattern, such as the synchronizing of women’s menstrual cycles with the phases of the moon or with one another in a group.
Yes, brainwave entrainment is based upon science. It has been scientifically proven to work, and to benefit the brain in all kinds of amazing ways. Yes people use things like EEG machines to read how it works on the brain. BUT, this does not mean it is overly complicated, and it does not mean that you have to be overly techy or scientific, or have any experience in neurology at all to create a brainwave entrainment audio or understand how it works.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement.