I work in a noisy cube farm that is often distracting. I've been unable to correct the noise problems at their sources and I don't want to wear headphones or earplugs, so it appears that using a white-noise generator is my other option (as recommended in this answer to a related question).

What do I need to know to effectively use such a device in my workplace? Does the type of noise matter? Does the type of sound produced by the generator matter -- steady hum versus varied (like a fountain), range, volume, etc? Is under my desk a good place to set it up? I haven't found any sources that discuss mitigation for different types of office noise.