Google it, make sure it is atleast 2 minutes long so your brain gets the effect
I did some research, only some will get the time-distorting(or whatever) effect, and there are better things to do the use white noise, such as what that last post said, but I find that white noise works.
What it does is get your brain into timing in a different pattern and your brain will use that, and the rest of your senses fail(lack for better word)