Any Sounds Analysts?

[StarSwirl05]

https://www.youtube.com/watch?v=zbjOEGP3c3k
Can any of you identify the sounds (that are NOT birds)? I've posted the info about them from what I've gathered in the description but just in case:
1. The sounds occur between 6:30 AM and 7:00 AM EST each morning.
2. They are low-pitched
3. The "cycles" last about 2 minutes each.
4. Although mechanical, being machinery is unlikely due to the precise time window the sounds occur.
To help, there are annotations in the video, except at the end because that one is loud and clear. Crank up your volume to better hear it. I haven't asked any neighbors about them but I doubt they're up at this hour and/or home. Plus one of the neighbors we have isn't really caring about anyone around them.

[Ionn]

Didn't really hear much in the video except right at the end but I've heard of similar cases that sound super freaky. This may be a case of atmospheric reflection. When a cloud layer in the atmosphere is juuuust right, sound waves will bounce off of it & back down to earth, sometimes hundreds of miles away! The reflected noise is usually low-pitched because low pitches have longer, 'stronger' wavelengths which take longer to dissipate than the short wavelengths of higher pitches, so if the noise has traveled way up into the atmosphere then back to ground many miles away, most of the higher pitches are long gone, leaving only very odd, warped sounding noise.

[StarSwirl05]

Didn't really hear much in the video except right at the end but I've heard of similar cases that sound super freaky. This may be a case of atmospheric reflection. When a cloud layer in the atmosphere is juuuust right, sound waves will bounce off of it & back down to earth, sometimes hundreds of miles away! The reflected noise is usually low-pitched because low pitches have longer, 'stronger' wavelengths which take longer to dissipate than the short wavelengths of higher pitches, so if the noise has traveled way up into the atmosphere then back to ground many miles away, most of the higher pitches are long gone, leaving only very odd, warped sounding noise.

I did add annotations that point out the short and still audible noises. If there's a way to send MP3s via PM, I can send an MP3 of the file where it's not only clearer but doesn't include any bird sounds.

[kaoskat]

You know, we have some insects/frogs/toads around here that make similar sorts of ringing sorts of sounds that always sounded weird and unanimal like to me until hubby could spout off what they were. Maybe that's the case here too?

[StarSwirl05]

I had considered animals. In fact I first thought it was some kind of insect. I live in NJ though so I'm not sure you'd find the culprit if it is indeed an animal.