Noise is either really clever or really stupid: it generates “pink noise”. The site says:

Also known as a signal with even power distribution on a logarithmic frequency scale, pink noise masks background noise to help you concentrate. Now with source code and white noise, for those less colorful. Drown out annoying roommates and co-workers today!

I’ve downloaded it and I can confidently say that yes, it does indeed produce noise.

[Free, Mac only.]