I have used white noise or waves for a long time to drown out outdoor noise around me.
My initial start with this kind of stuff was listening to various stations on somafm.
I like finding music that fits well in the background, isn't too engaging or something I'm familiar with, and hopefully devoid of vocals so I kept looking and came across a few instrumental tracks on itunes.
There's maybe a reason babies benefit from wave/sleep machines. White noise does have an effect that can aid in focus and concentration, science, placebo, or otherwise, I'm happy for the sustained productivity boost I've been able to have for several years.
I did buy brain.fm on a whim a while back it has replaced simplynoise or more to that point. If there was a bit more information published on how it was put together I'd be interested, and if not, I'd probably keep using it.
Would like it to be a downloadable or app that I could keep with me. Some things aren't for those who can't put themselves in other people's shoes, or imagine something may work for others that doesn't seem to be imaginable or work for them.