I have changed my background sounds since my May 19, 2017 post above. I no longer listen to youtube videos as I write.
I now use http://www.mynoise.net
, both the web-based and iOS-based versions.
For folks who enjoy ambient sounds/noise rather than music (I know the title is "Music for writing", sorry!), I cannot stress how cool myNoise is.
There is a *huge* assortment of choices, from instrument based pads, to weather, industrial sounds, variations of white noise, plane cabins, chimes...you get the idea. And they are continually adding new ones.
The myNoise interface is basically a sound mixer. Each sound comes with 10 sliders that let you adjust different aspects of the generated sound. So one sound, say Thunder Storm, can be tweaked to be a full on howling storm with rain and thunder, or only the sound of gentle rain drops, or rain & howling wind, or distant thunder, or some variation thereof.
The other cool feature for me is that you can stack sounds on top of each other. So if you like that droning tones generator, but want to add a pinch of distant thunder and a tiny sprinkle of airplane cabin, you can do that, and then save your creation.
I believe you need to be a donor to access this feature in the web version, although as a non-donor you can simulate it by launching multiple browser tabs or windows. It is free in the iOS version.
Regarding cost, the iOS version is free, and they start you out with 5 or 10 sounds, and then you can sample and purchase additional ones as you like. I ended up purchasing all current & future sounds on the iOS app for a flat fee, and donated to the web-based version to get access to the sound stacking feature.
I created a stacked sound that I use only for writing, and it seems to help me focus. helps me get into the zone more quickly. I guess it's a Pavlovian thing: with the sound in my bluetooth headphones, I know I'm supposed to be writing. (In addition to the ambient sounds, I also have typewriter clacking in my headphones generated by laptop key presses -- I'm obviously into audio reinforcement!)
This setup works really well for me. Hope it helps someone else,
* Not affiliated with myNoise, just a happy customer in evangelist mode this morning.