I got a report today from a man in England on his experience prior to the quake over there:

About a week before the Midlands Earth Tremor on 28th Oct. I became aware of a constant 'hum' in the house - which can best be described as sounding like a distant car engine idling. It was most noticeable at night and it took me a while to get off to sleep as the sound was quite strong.

The sound or vibration seemed to be resonating the house - we live in a modern detatched house with plasterboard inner walls which tend to resonate at very low frequencies.

I could just detect this hum outside if it was quiet enough. My wife could not hear this sound at all and was getting fed up with me often asking if she could hear it! I thought the hum was being caused by vibration from the local Gypsum plant or maybe from a turbine shaft at the local power station a few miles away .

After the Quake the hum changed from being constant in nature to fluctuating - still quite noticeable but of a 'watery' or ripple type of sound.

As days have passed the hum has faded away and now it is barely audible most of the time.
I find it a little disturbing that nobody else has reported hearing this 'hum' and nobody around me seems to have noticed it.

It might well have been an industrial vibration coincidentally occuring before the quake. Who knows?!!
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Canie