Researchers have discovered some interesting effects of background white noise. First, as the noise increases the perceived taste of food becomes blander and crunchier (which helps explain airplane food). Second, for students with problems focusing, white noise brought their performance level up to that of other students. Unfortunately, the noise worsened the performance of normal students—so there’s not a one-size-fits all solution here.
From personal experience, I like having background noise on all the time. For example, I turn on the radio when I go to bed. And back in my college days I had music playing pretty much 24/7. It seems to help. I know other people, however, who can’t sleep or concentrate when there’s noise in the background.