I experimented a lot with different audio backgrounds during the writing phase of my phd. While music could be energizing, it quickly became a diatraction, whil

I experimented a lot with different audio backgrounds during the writing phase of my phd. While music could be energizing, it quickly became a diatraction, while in a silent environment I easily felt tired or even sleepy. What worked best was an endless loop of 'brown noise', (similar to 'pink noise' or 'white noise') , it blankets out all other sounds but I don't hear it any more after a few minutes.