It's counter-intuitive, no? Actually though, the trick isn't to add more noise. Or... specifically, I suppose we need to first establish that the noise isn't th

It's counter-intuitive, no? Actually though, the trick isn't to add more noise. Or... specifically, I suppose we need to first establish that the noise isn't the problem; noise is easy to tune out. Your brain is doing it right now: focus on your surroundings, and odds are there's the low hum of some air conditioner, or the whine of a CRT monitor, or the sound of that florescent ballast down the hall going out, or whatever. You barely even notice these things, because your brain is good at filtering out anything repetitive or constant. What kills productivity in an office environment is actually signals that cut through that noise. Phones ringing, conversations between coworkers, printers whirling to life, someone opening a cellophane wrapper and chewing on a candy, etc. Most of these things aren't useful, but they're distracting, because your brain is tuned to constantly be on the lookout for new audio signals to shift your focus to. This is probably a survival instinct, as becoming aware of an approaching predator is important to avoid becoming lunch. In an office, the goal isn't thus to add more noise, but to mask the noise, so that it is less distracting. Music is not "more noise," but more like a big, obvious beacon of focus. You might think of it like a controlled, intentional distraction. It's juuuust enough of an audio signal that your mind can keep its focus in one place, and just barely loud enough that when your coworkers phone rings, it isn't quite so jarring. That tiny, tiny little adjustment in the relative weight of the signals can make all the difference in the world, preventing you from unnecessary context switches throughout your day and helping you to maintain flow while working on a complex task. It's not perfect, no. Obviously the perfect environment would be 100% in the control of the worker, who could dictate the noise level and comfortable temperature and everything else on a personal level. But, well, the real world isn't perfect, and it can be good to have options. :)