http://gethighnow.com/binaural-beats/
Binaural Beats 
Choose a Binaural Beat to suit your mood from the below. Note that in order for Binaural Beats to work, they must be played though headphones.
WARNING: DO NOT listen to Binaural Beats while driving, operating equipment, or any other task that requires concentration. DO NOT listen to Binaural Beats if you have experienced seizures in the past or have epilepsy. Those with heart disorders or taking mood-altering pharmaceutical drugs should consult a doctor before trying. We’re serious. Use common sense, people. Sure, Get High Now (without drugs). . .but don’t die! 

How It Works

When two tones of specific frequencies are played through headphones, the brain can become confused and produce its own, imagined tone—a three-dimensional audio hallucination heard only within the head of the listener. The frequencies that produce this phenomenon are known as Binaural Beats.

What is happening is that the brain is not used to hearing frequencies in each ear so close together and with such intensity—these sounds do not occur in nature and so a mechanism in our brains has not evolved to understand them. Instead, the superior olivary nucleus, the area of the brain which controls aspects of three-dimensional sound perception, bridges the difference between the varying frequencies in Binaural Beats with a common “third tone” in an attempt to normalize this audio into something we can understand. What’s weirder is that each person hears the “third tone” differently: People with Parkinson’s disease can’t hear it at all; women will hear different tones as they move through their menstrual cycle.

Binaural Beats were discovered in 1839 by Prussian physicist Heinrich Wilhelm Dove (1803 – 1879) but they didn’t gain much public interest until the early 1970s. Then, scientist Gerald Oster postulated that the brain wasn’t solely affected by Binaural Beats. He tested this theory with fMRIs and found he was right. The neurological system as well as other parts of the body responded to the frequencies.
Since Oster’s discovery, Binaural Beats have been used as cure-alls for everything from impotence to bulimia. Spurious, right? Sure, but the difference between Binaural Beats, and, say, magic healing crystals, is that Binaural Beats have been clinically shown to physically affect the listener’s brain and body, even triggering the pituitary gland to flood the body with good-feeling hormones like dopamine. In other words, Binaural Beats are proven to get us mentally, physically, physiologically, biologically, scientifically, inextricably high.

Remember that people hear Binaural Beats differently, and some may have trouble hearing the “third tone” at all. How will you know if you can hear them? Say you can, get some headphones, and try them out. Every single member of HighLab heard them, and regaled Binaural Beats as one of the most fantastic audio highs in this fantastic app. What are you waiting for?