Outside stimuli become a lot less distracting when you can't hear them. Using noise-canceling headphones is a highly effective way to focus attention on the task at hand and block out any distractions. I use mine even when I'm not actually listening to anything — I find the noise-canceling effect incredibly helpful to stimulate concentration on its own.
When I do play music or sounds, I focus best with either white noise or binaural beats (more on that later). You have to be mindful of what you're playing in the background, because these sounds could easily hinder your concentration. According to Healthline, you may want to avoid anything with lyrics in a language you understand, as this can be more distracting. The same goes for music that's too loud or fast-paced, and songs you either really like or really dislike.