Pink noise (http://en.wikipedia.org/wiki/Pink_noise http://en.wikipedia.org/wiki/Pink_noise) is good, too - it's white noise which has had its frequencies adjus

Pink noise (http://en.wikipedia.org/wiki/Pink_noise http://en.wikipedia.org/wiki/Pink_noise) is good, too - it's white noise which has had its frequencies adjusted logarithmically, so instead of being mostly high-end hiss it sounds like rushing water. I made a 16ish minute sound loop somewhere, but don't have it on hand at the moment. (It's just the loop on wikipedia, concatenated repeatedly.) Also, isolation tanks can be nice.