Does a monotonous drone count? That's what one of my X's was like with her non-stop talking. LOL
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Probably the long "ringing" of the earth from a major volcanic explosion - I believe I have seen reports that the sound blast from Krakatoa circled the earth several times and the seismic waves were detected on more than one passage around the earth.
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The microwave echo of the Big Bang...
It took 13.7 billion years...
It took 13.7 billion years...