Pink Noise is like a “warmer” form of static
Our brains quickly learn to ignore it, but it saturates the auditory system and makes it easy to tune out other noises. I find that when I am stressed, I need a quiet environment without distraction to study effectively. This is a tip that works about as effectively as any earplugs or noise-canceling headphones.
If you take a source of pink noise, even a convenient youtube video (search or use the one below), and play it softly through headphones (even earbuds) you can make everything else sound a lot softer. I’ve used Skullcandy earbuds and they work pretty well. They block my ear canal pretty completely and then the added pink noise makes everything else fade out.