Can somebody explain this?

I'm in Toronto, and at around 1:30 A.M in April, there was a large mid-deep humming sound over my house. As i walked from my bedroom to the sky light, that sound stopped. Any ideas?

sounds like youve been visited my friend

if it was a low frequency sound then your ears struggle to sense what direction it was comming from (like the way you have a seperate subwoofer on your audio systems and you cant pin point it when its set up correctly)

also with humming sounds , its usually the vibration of other things that you hear along with the sound , could it be that it was just rattling the rafters?

failing that , it was a huge cloaked klingon destroyer looming over your house waiting to abduct you

Electrical transformers can sometimes create an annoying low frequency sound. Maybe the kid next door, installed one of those infernal 500 watt amps with three 32" woofers in his trunk.

[edit on 04/9/6 by GradyPhilpott]

Neighbours don't have woofers. There are no kids on my street. Just seniors. This sound was coming from directly above my house.

There was no vibration. It was low frequency, but it was pretty loud. I'd say maybe 20-30 db.

My room is on the second story. The transformers are nowhere near me.

Well, I guess that leaves us with the Klingon ship theory.