"Hearing" the explosions in North Korea

International experts are far from convinced that North Korea actually conducted its first H-bomb test, which was reported by the country this week. In the meantime, South Korea is blasting pop music, weather and news broadcasts and recorded criticisms of North Korea with loudspeakers on the border. Speaking of loudspeakers, turn up the volume on your computer because Associate Professor Zhigang Peng is allowing people to hear what the explosion (and its predecessors) sounded like when their sig