On Wed, 01 Jan 2014 11:14:40 +0000, Lobster wrote:

Interesting related piece on the likely cause of the "Bristol Hum":
http://tinyurl.com/k8yw55d (or http://www.bristolpost.co.uk/Bristol-s-
mystery-hum-solved/story-11277492-detail/story.html)

I find it very frustrating that so-called "experts" say that the noises
are in people's heads. It's obvious that many people have deficient
hearing, and those people should not be consulted about tracking down
noises that DO exist, and they should be ignored when they say they
"can't hear any noise".

In many cases it's just a distant machine making the noise. The frequency
is so low that it could travel for miles. I am able to record the noise
that ship's generators make two kilometres away. I can drive there to the
ship and listen to the same noise. I can tell the direction of the noise,
and so can other people who live in a different direction.

The noises may be stronger in a room that has the right dimensions to
amplify the sound as it resonates from one corner to the other.
Hanging heavy drapes in the room or putting carpet on the walls can help
- I tried that!