Anyone else hear a strange vibrating sound around 1am?

Around 1AM I began hearing a strange pulsing, low vibrational sound…

Like "Wommm-Wommmm-Wommmm" over and over again.

Lasted about 5-10 minutes

And it sounded like it was coming from outside, although I couldn't see anything when I looked.

Was wondering if anyone else heard that sound? (Or anything similar?)