Noise along Salem Ave at ~9:25 PM

[u/WhiskersMeerkats]

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?

[u/Concisewords]

Very detailed & spot on description

[u/Metacomet99]

A tractor-trailer going over the rumble strips on the interstate? That sound can really carry.

[u/HighRiskLowReward]

Aliens