This thread is certainly off-topic, but since I already have already been branded as a felon in that regard I might as well add a post here.. A couple of good articles on this subject are In Quest of Meteor Sounds, Sky and Telescope Magazine, December 1985 pg 623 and Detecting Natural Electromagnetic waves, Scientific American, May 1996, pg 98 Space Shuttle reentries produce the same effect and are a predictable source of ELF and VLF, there are also reports of sounds being induced in conducting objects during Shuttle reentries by the same effect. Dale Ireland Astronomy Page http://www.drdale.com Comets, Satellites, Eclipses, Photography, Fabrications