I've listened to a few of these now and they are definitely not easily explained. I use high quality DJ headphones, and I can clearly hear electrial impulses, rhythmic bleeps and the bass is highly unnatural. I will not listen to them anymore so I don't know if this example fits this description.

Originally posted by StealthyKat
I tries to figure out what it could be, but came up with nothing. It definitly came from the sky.....

So are you thinking some kind of aircraft? Or could the source have been on the ground and it just reflected from the sky?

I have a suggestion next time you hear it. Cup your hands behind your ears, which blocks the sound coming from behind your ears. Then as you rotate your body, see if the sound is louder in any particular direction. If it is, then you know where to look for construction equipment, etc. I thought there were a lot of great suggestions in this thread on what it could be, like the road eater.

I once heard a sound I couldn't identify, and it frustrated me a little bit. But I was 20 miles from a military base and I suspected it was coming from there, though I never confirmed it. Thanks for recording it and good luck figuring out what it is.

Originally posted by ThinkingCap
You most likely live near an private underground military base.

Could extend for miles.

Literally could be an underground train.

Not sure though. As a person who has been following this phenomenon on ATS for quite a while, I am convinced that the military has a hand in this. The sounds are far too steady paced to be something natural.

Could you describe the sound more please though? Quality was iffy - great video nonetheless.

I think noise complaints of this kind are usually assosciated with rail lines and windmills.

I couldn't say, but usually a windmill of rail line is to blame. And they don't necessarily have to be that close to where you are, often even miles away and you could be completely oblivious to their existence.

Originally posted by StealthyKat
I wonder how far away it could be for me to hear that? I have driven around on two occasions to see if there was anything like that going on....but nothing. This is out in the middle of nowhere, not much going on.

Unfortunately Google doesn't update their satellite imagery too often, but they usually show the date of the imagery, there's even a time slider in Google Earth.

You can cover a lot more area in the satellite image than you can driving around. Maybe there's something 8 miles away that you don't even know about that shows up in the satellite image? Sound can carry, especially if you're downwind from it. I'd look at satellite imagery of the surrounding area if I was you.

Originally posted by Skewed
I thought I was hearing the humming/rumbling sound as well. Took me a while to figure it out but finally tracked it down to a train in the distance.

A TRAIN? For an hour or more? I think not. I have lived near trains and further away from trains - and NEVER have I heard them for more than about 10 minutes.

I don't think it is a train.