these couple of posts point to the explaination(s) i have:

posted on 25-1-2012 @ 22:12 by Vasa Croe
The only thing I can think of that this sound compares to is the hum of a squadron of large prop planes above the cloud cover in the air like what you hear/see in the old WW movies with all the paratroopers about to jump out. Very low humming that fluctuates in intensity.

posted on 26-1-2012 @ 06:35 by Grifter81
Interesting you should mention that, my Grandfather used to say you could tell from the ground if it was a luftwaffe squadron overhead because their engine noise 'ebbed and flowed' while RAF/USAF remained a constant hum.

tarifa37 posted on 26-1-2012 @ 07:59: I would say its a helicopter hovering some distance away.

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these sounds, a low droning sound in this case... in Atlanta & shared in the OP
~could be the sounds of a 'city' being reflected off a temperature 'dome' high in the atmosphere~


in the Black-Ops realm... the droning or even growling sky sounds may be from the black triangular UAVs which autonomously navigate in the night time skies (only seen one once in Phoenix in dec. 1996)


on the other hand, in a more metaphysical bent, the droning may come from actual sounds of WWII bomber squadrons that have traveled through time... the aircrafts being invisible at some 30,000 ft
~we might be experiencing an Echo of the 1941-1944 era~ and the phenomena is not limited to the European or Japanese Theatre's of war.



i personally prefer the weather angle as the likely cause...
let's say Haarp energized the upper ionosphere... that might cause that layer of air to form a kind of bowl or dome over large regions... so the noises of a city are being reflected back to the ground or there may be a tunnel effect taking place that mimicks the sounds that come from a Sea-Shell held to one's ear... hence a faint whooshing that sounds like waves on a beach, undulating, for as long as the atmosphere does not kill the effect with cross winds or other disruptions like storm fronts, etc


i might add that high altitude layer of dense air that reflects ground noises,
might just be reflecting the continual stream of jet engine noise as well, and resulting in the drone like sound instead of roars and screaching/whining of the turbines in those jet engines.


thanks,
~when does Pebble Beach golf start today?...try to distinguish the sky sounds there, if not scrubbed out by the sound engineers on TV

First of all thanks for the video and for inspiring my first post. I have been reading this blog for a quite a while but this post really got my attention. Now, I split my time between Buckhead (Atlanta) and a farm just south of the city. Being in both urban and rural areas I am used to the sounds of military planes from the surrounding air force bases, constant traffic of the Hartsfield-Jackson Intl. Airport and the wide variety of crop dusters/recreational planes/etc. that are fairly common. It could be a plane but it's not like anything I've heard in our area before. Tonight I am at the farm and I plan to spend a little time outside later this evening to see if anything can be heard. Not far from the farm is an area known locally as Flatrock. Recently reopened as a state park, growing up I always heard odd stories from hunters or hikers in that area of strange sounds/animals. For years the area was closed down by the government an no one really said why. Later I spoke to a biologist who told me that rare or thought to be extinct plant life was allegedly found growing there and test were being done. Our state has a deep connection to the government so who knows. Like I said, I will try and make a few observations this evening and if I find anything I will post it here.

I dont know, all these sounds being reported could be anything. Or a hoax. I guess i need to hear it for myself.

Just wanted to mention:
I live in a very small quiet town. An airport is 20+ miles straight up wind from my house. I live in the woods and I can hear the same sound when the night become quiet after 12midnight. The wind currents makes the sound levels change. I have listened to planes from a distant seemly sitting on the tarmac just running their engines as hard as they will go. Then poof it stops.. I always contributed this to the small commercial airport near. IN GA. Even the turkeys will gobble in the morning 4am when the jets are lighting up the engines.

Also, there is a concrete plant ( I Believe) is making a sound, that sounds the same as some of the sounds in the videos. It can very very annoying if I cant sleep. This is located about 5 miles down wind. I am not sure its the concrete plant making the noise I just always assumed it was seeing as it was so loud and so common in the past few years. Most of the videos I have watched about this sound, sounds like planes in some fashion.

I will pay more attention more so now and see if I can get a different mental view of anything different next time.

CSRA area.

Ahhh, how coincidental with the Savannah River Site, nearby you...