FASTEST WAY TO EARN THIS JUST RIGHT THERE :
What could be an easy way to earn this, is to use my current method (while I'm writing, my playlist is running). You just need to have your computer (works for Win7/Win8, others I don't know) connected on the same network of your Xbox One.
Download Audacity (free) for your computer, then record half a second of sound in this software, then export it as a .wav file, and then copy/paste it in the folder to be sure it will not bug later (you may even copy/paste it more times just to be VERY sure of this ! ^^)
And now, the only last thing to do (depends on your configuration) is to select those files, click right and select Play to : Xbox-SystemOS or whatever you called your Xbox One.
Now, go doing whatever you have to do, you can go sleeping, shopping (no school because it's holidays !), working or whatever you want ! (I'm going to the mall right after writing this :P)
Hope it works for you because it works for me and my best friend ;)