For anyone that doesn't know, binaural beats are frequencies generated by playing 2 different tones in the left and right headphones, and your ears and brain percieve it as a single frequency. You can use them to synchronize your brainwave frequencies in different ways.
There are 4 main frequencies:
Beta: the highest frequency, beta waves are most prevalent when in a stressful situation or forced to focus on something
Alpha: associated with an alert but meditative state. good for learning
Theta: associated with deep dream states
Delta: associated with deep and healing sleep
you can find a bunch of free binaural beats on youtube, but the quality is compressed so I reccomend you download some in wav format or make your own with Gnaural.
Basically, binaural beats always work, as long as you're using stereo headphones. The reason most people give up on them is because of the whole idoser company advertising beats that are supposed to re-create the high from certain drugs. Binauaral beats don't get you high, don't expect that. But I've been using Gnaural for a few days now and it's really helping alot with everything.