Beta brainwaves are next highest in frequency after alpha waves, occurring at 13 to 30 hertz. Beta brainwaves are what we experience every day as we are awake and using our analytic mind. Beta brainwaves are needed for concentrating on mental tasks, and when they are present for too long of a time, they lead to stress, anxiety, and even paranoia. Most people do not have trouble achieving beta brainwaves and in fact suffer from spending too much time in beta brainwave patterns. However, those with attention deficit disorder (ADD) who have problems focusing their attention can benefit from learning how to achieve and remain in beta brainwave states for longer amounts of time.
I’ve been on the brainwave vibe for about 6 months now, & I’m really diggin’ some results! I find that there are certain frequencies, I guess, that feel right and comfortable to my mind; I also find that I can physically feel the area of my brain that “pure” (no frikkn ocean waves) tones are affecting as I listen to them. This occurs the moment I hear the sound. Kinda like energy, a brain tickle. Spooky & awesome!!
In fact, there is more to answering this question than meets the eye. As someone who’s also been skeptical enough to do the research, I am more than happy to explore the issue in great depth. The important thing to address here is what have you been told that Brainwave Entrainment would do?  Depending on whose site you’ve landed on you may have been promised different things.  The promised benefits of this type of product are a long list, and more things are still being added to it.  You may have been told that brainwave entrainment would help you meditate deeper, and rocket launch your spiritual evolution from doing so.  You may have been told that it would help your brain release positive neuro chemicals and anti-aging hormones that would improve your health and help you feel more positive emotions, overcoming anxiety, and you also may have been told that listening to brainwave entrainment on a regular basis would help your brain evolve, building a higher threshold to mental and emotional input, growing neural pathways, and synchronising the two hemispheres of the brain.
The activity of neurons generate electric currents; and the synchronous action of neural ensembles in the cerebral cortex, comprising large numbers of neurons, produce macroscopic oscillations. These phenomena can be monitored and graphically documented by an electroencephalogram (EEG). The electroencephalographic representations of those oscillations are typically denoted by the term 'brainwaves' in common parlance.[4][5]