Just saw this, could explain things? I live more or less at sea level in an old growth forest about 100 years old trees more or less. The soil is sand and clay with lots of that iron sand leached deposits. The iron content could be creating a field effect I guess. It's away from roads and highways and railways, and no pipe lines within a few miles. So not sure if its the lack of noise that can allow the hum to be noticed or it's just part of the environment. Mostly noticed inside the brick house. I am going to install low e windows with sound proofing on the now open porch to see if it has any effect. Will let you know.
FYI Quietest place on Earth mutes all sounds, messes with your head By Tecca (Credit: Orfield Laboratories) NASA heads to a lab in Minnesota to put astronauts through acoustic torture tests By Mike Wehner, Tecca If you've been to a crowded airport, sporting event, or even a kid's birthday party lately, a little peace and quiet might sound like the perfect thing to help you kick back and relax. Just don't let things get too quiet, or you might drive yourself a wee bit insane: the anechoic chamber at Orfield Laboratories in Minnesota can mute 99.99% of all sound, but visiting the silent oasis isn't as calming as you might expect. The room holds the current Guinness World Record as the quietest place on the planet, and companies from all over the world seek out its unique acoustic properties. The walls of the chamber are lined with sound-absorbing baffles that can capture noise and mute it in an instant. This allows companies — both Whirlpool and Harley-Davidson have visited — to test just how noisy their products are without the risk of outside interference. But while the super-silent oasis is a great testbed for various products, it holds a darker side: silence, it turns out, can put a great strain on the human brain. Researchers at NASA test the room's unique acoustic capabilities on humans rather than hardware. The noiselessness is used to simulate the silence of space — an environment astronauts would be well served to grow accustomed to. What they've found is that when all outside noise is removed from an enclosure, human hearing will do its best to find something to listen to. In a room where almost 100% of sound is muted, people begin to hear things like their own heartbeat at a greatly amplified volume. As the minutes tick by in absolute quiet, the human mind begins to lose its grip, causing test subjects to hallucinate. NASA then monitors how the would-be space explorers react, and whether they can get past the very obvious awkwardness of seeing or hearing things that aren't actually there. According to lab officials, the longest anyone has lasted is 45 minutes before being allowed to hear the sweet sounds of planet Earth once again. In the end, the chamber has proven a valuable scientific tool, just don't plan on renting it for some peace and quiet — it may do more harm than good. -- You received this message because you are subscribed to the Google Groups "Hum Sufferers" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/hum-sufferers?hl=en.
