Brainwave Entrainment Is A Natural Thing

Brainwave entrainment is based on the principle in physics that proposes that two cycles will naturally synchronize with each other in order to work more efficiently. The brain's natural frequencies will attempt to duplicate or entrain to the frequencies of an outside stimulus.
This is called Frequency Following Response. Sound and/or light patterns or rhythms produced in a specific way for a specific effect are presented to the brain. Shortly thereafter, it copies that pattern and produces the same specific effect.
Simply put, like attracts like.

You've been entertaining your brain since you were a fetus growing in your mama's womb. Your little brain quickly and naturally entrained to the sound of your mother's heartbeat. If she was calm and relaxed, her heartbeat slow, your brain waves matched that pattern and you were calm and relaxed...your heartbeat slow. If she was excited and her heart was beating fast and hard, your brain duplicated that pattern and you were excited, your heart beating fast and hard. In that case, your brainwaves signalled your body to kick up a storm.
Nobody got any sleep that night.
That's entrainment.
Have you ever fallen asleep listening to the raindrops falling on the ground outside your open window? Your brain followed the rhythmic patterns of the sound, matched it, and produced brain waves that put you to sleep.
That's entrainment.
You listen to designer music with specially placed frequency patterns and your brain follows along, changing its frequency to match that pattern inducing a state of mind

That too is entrainment, and it is as natural as the other two examples except that it is focused with intent.
And what's cool about brainwave entrainment, is that you can formulate sound to target certain areas of the brain to produce a desired effect. You don't have to wait for the next rainfall to cure your insomnia. You can use a specially designed brainwave entrainment mp3 and achieve the effect or state of mind, quickly and effectively.
And you don't have to do anything different than when you were in the womb or in bed by the open window. You just have to listen.
Brainwave entrainment can be used for immediate effect, like reducing anxiety, or for long term effect where it retrains the brain at a micro-anatomical level--like when you want to raise your IQ to pass that big exam.
You tune or direct your brain for the desired outcome.
You can use brain training for a temporary result, like the sound of the rain putting you to sleep that night, or a permanent result, like removing an emotional block and changing who you are and how you are. It all depends on how often you use the session.
You can use it to increase your libido, or to teach yourself how to use your hand again, after a stroke.
Repetition of entrainment, spontaneous and induced, will produce new neural pathways and change the structure and function of the brain.
I wonder if a person who lives by a rushing waterfall has their dominant brainwave frequency permanently changed. It stands to reason that this would happen because of the brain's plasticity and ability to grow new neural networks. It works that way with designed brainwave entrainment too.
The brain follows and synchronizes itself to outside stimuli such as sound, light, smell etc, whether made by man or not indicating that....
Brainwave Entrainment is natural thing, too.