Those white noise things are nice, but for about the same price you can get a Honeywell HEPA Air Cleaner. This will make a nice white noise plus they have "Filtration which removes 99.97% of all particles down to 0.3 microns in size, providing protection from dust mite allergens, mold spores, tobacco smoke, pollen, animal hair and dander, bacteria, viruses and other harmful airborne particles."
I have one of these and they work wonders for you nose and well as making wonderful noise.
Here is the link for info on the product:
http://www.comfortliving.com/honeywell_airclean.htm
Sorry to drift so far off topic, but I can't tell you how much this little sucker has changed my life. My wife suffered from dust related problems for years until I picked up one of these, then like overnight she was cured. If you have any problems related to dust or mold spores it would be worth your while to read up on these air cleaners and see if one could help you.
Just as a note, I didn't purchase my unit from confortliving.com, I got it at Home Depot, but I have purchased replacement filters from them without any problems.