About 10 years ago I had a spooky experience, which later turned out to be probably just an aircraft passing overhead.
I was out walking with the wife when we heard the sound of air collapsing above us and traveling from horizon to horizon. We were walking along a golf course with ravines and tall pine trees, about 2 miles from the International Airport, so I expected to see a jet aircraft pass overhead.
But nothing passed and the sounds began to lapse, then returned getting louder. They continued for about 2 minutes, and no aircraft in sight as we mounted a hill and surveyed the horizons. Additionally, at the hour it occurred, the airport was closed for approaches/departures.
Since that time I have heard the sounds again, but with aircraft being visible. I surmise it was an aircraft, but I know it was incredibly spooky thinking it was an aircraft, when no aircraft could be found for its cause.
By listening to the youtube video, I wouldn’t be surprised if some sounds were modulations of Osprey flyovers as they transition from hover to flight mode.
Another thought I had regarding the sounds would be to query if they were perceptible by out or inner ear. Some ultrasonic speaker systems are inaudible except for specific ranges in specific frequencies, and in some cases are not perceivable in outer ear transmission, but only resonate just inside the inner ear. If somebody were tuning a weapon system to target mass audiences from afar, the sounds might be perceived as replayed to bracket their targets.
I think the sound was and inner and outter ear experience. I felt and heard it. Sometimes I think it was a groan of the earth and sometimes I think it was blasts of sound from the sky. I just never heard anything like it before. The ground did not move.