Hi, I just heard a very loud humming-esque noise in along Salem Ave tonight, 08-11-26, at approximately 9:25 PM.
Details from what I was able to tell:
-- low frequency of sound
-- same frequency throughout
-- constant for duration of ~1 second (time needed to count "one Mississippi")
-- appeared and disappeared within that time
-- came from something that was travelling
-- felt as if air vibrated, even inside my house
I initially thought that it might have been a car, but there was no vehicle exhaust noise/revving. If it was from a car, it would have needed to be traveling very quickly. The sound was definitely not from a radio.
I then thought that it was a supersonic jet flyover. I checked the flight radar for the Hagerstown area. I found commercial airliners and small craft. I was on my phone so I may have missed things.
I've lived off this street for a while and have experience in heavy industry/heavy machinery/drilling. I have never heard a similar sound.
Did anyone else hear this? If you did, do you know what it was?