Binaural beats of 40 Hz focus on the gamma waves of the brain, which is documented as the fastest frequency range in the brain.  The gamma frequency is where the brain links and processes information, for example, you touch a hot stove plate, the sensation is extreme heat and the process includes the feeling of pain and the removal of your hand from the plate, although this whole process only takes a few minutes it is all done in the gamma range of the brain. 

It is easy to see why the gamma waves are the fastest frequency, they are also the busiest, which makes the binaural beat therapy of 40 Hz one of the easiest binaural beat therapy to undergo and a lot of people who do not experience any results from other forms of binaural beat therapy have been known to experience small changes from binaural beats 40 Hz therapy. 

People who go for binaural beats of 40 Hz therapy usually want to boost their mental processing speed, increase their perception of reality and obtain a richer sensory experience.  People who have gone through binaural beats 40 Hz therapy have reportedly been able to learn faster and maintain their focus on one subject as well as showing an increase in their IQ scores. 

Although binaural beats of 40 Hz have the above benefits, there are people who do not experience the benefits and it is important that people with epilepsy do not attempt any forms of binaural beat therapy.