“I ADORE mynoise.net. It’s an archive of customizable sound generators with everything from music, nature sounds, sound cancelling, ambiances, and meditative drones etc. I focus best with some kind of white noise, and this website has a ton to choose from and it is free. My favorite feature is the customizable, animated sliders so you can listen to storms that ebb and grow automatically. It is great for TTRPGs too. The sound engineer who runs it has put together all kinds of specific settings like churches, cities, forests, faires, dungeons, etc. Seriously, people should check it out.”