I also hear ear tones at times - I haven't kept a log and I wonder each time if it means something. I heard a really loud long one the day before the Hector quake - maybe one of these days I should start keeping a log - But - if we can hear something then that has to mean that there is some sound being generated - something mechanical should be able to also hear those sounds. I don't have a clue as to what the frequency may be but it is an interesting thought.

I'll vote it a foreshock.

Canie