I noticed these white noise generators in my local Community college library and a few business offices. They produce the same whooshing noises as modern HVAC

I noticed these white noise generators in my local Community college library and a few business offices. They produce the same whooshing noises as modern HVAC systems (heating, ventilating, air conditioning) and seem pretty effective, after spending a few dozens of hours with my linear algebra and D books. http://www.marpac.com/Marpac-Dohm-NSF/dp/B006Z8J9I0 http://www.marpac.com/Marpac-Dohm-NSF/dp/B006Z8J9I0