Earthquakes do produce a very unique sound, no question about it.
I'm in full agreement with Cindi that cats and dogs can definitely sense a quake before it hits. I've witnessed my cats exhibit very odd behavior (even for cats !) just before a quake occurs...then they're MIA for a full day or longer afterward...depending on the severity of the quake.
I've lived in "earthquake central" my whole life and they STILL freak me out.
