In a big city, silence is a luxury — second only to quality sleep. Wherever you live, though, white noise can make it easier to get both at once.
White noise is really just the combination of noises that are humming at different frequencies. What you end up with is a soothing kind of muddled nothingness (e.g. radio static). But when we say "white noise," we usually mean "ambient noise," of which white noise is one variety. You might have also encountered pink noise (think: steady rainfall or a bustling coffee shop) or the even deeper brown noise (think: a waterfall or traffic rumbling in the distance).
It makes a little more sense if you think about light: Light with a similar frequency pattern to pink noise, for instance, would appear pink. Same goes for blue and green noises. And white noise, like white light, is what you get when you combine all the other frequencies out there.
Essentially, all of these noises work by masking other potentially annoying sounds (hello, squeaky hallway door) and making them seem less alarming to your brain. That way, you can focus on your work or your ZZZs. Some people believe that certain types of ambient noise are better for certain tasks, such as playing coffee shop sounds in the background while you work and a fan while you sleep. And there is some evidence to suggest that pink noise might be particularly useful for sleeping.
But, overall, matching a specific noise to your activity seems to be a very personal thing. So, the best thing you can do is try a bunch of stuff out and see what works best for you. Continue on to see some of the most popular ambient noise machines and apps — and let us know what your favorites are!