Postcount 2

DIY a parabolic microphone with feed back blocker. Use Laptop with sound recorder with EQ on input, move lows up and down, drop/cut mids and highs. Look for your sound, if you cant find it try suspending a flat plate, of metal on neoprene washers on hard solid rock aim parabolic microphone at it and tent whole plate and mic with say 10 or 20 king size comforters and foil blankets that will tell you if it is coming from the earth. For more info look up research papers on sub sonic frequencies form space or earth.