The mystery noise driving the world mad [video]

Here's a good article on building low-cost devices to detect infrasound.[1] Most microphones and sound cards don't go much below 20Hz, so you need special equipment. It turns out there's lots going on below the human hearing range, and it can be analyzed.

With multiple microphones, you can direction-find, but you need huge separation in the infrasound range, because the wavelengths are so long. Human heads are too small for this. A useful trick would be to build some units that record a stereo signal - one channel infrasound, one channel a precision time track such as WWV. Space those round your town, and send back the files for synchronization and correlation. Good project in an area with hum problems.

The problem in Portland was traced to a bulk ship unloading machine. The addition of two mufflers fixed it.[2]

[1] http://www.techlib.com/area_50/infrasound.htm [2] http://westseattleblog.com/2012/12/the-hum-followup-calportl...

Do you hear a background hum?

Errr, now that you mention it, I guess I do.

It is driving the world mad. Is it driving you mad?

Yes I think maybe it is.

Did you hear the background hum before today?

No, but I definitely do now you've mentioned everyone else hears it.

This has come up in the local papers a few times here in Wellington, New Zealand. The prevailing theory is that it's a diesel generator on a ship in the harbour.

I had to disable every security measure just to get to a "we need flash" notice.

Anyone with a youtube link?

It's called tinitus. Flagging because pretty useless.