Raise your hand if you've ever personally witnessed the detonation of a nuclear weapon. For those of you with your hands up, please accept our admiration and respect, but for the rest of you, you have no idea what it was like. Don't feel bad, it's not your fault, but today you have a chance to see an atomic bomb test on video complete with the original soundtrack.
The vast majority of nuclear test footage soundtracks are fake, with the sound shifted, dubbed in or otherwise monkeyed with. How do we know this? Because someone just dug up a test film for a 20-kiloton atomic bomb from March 17, 1953, complete with the original (and remarkably high-quality) audio, and it doesn't sound like what you're probably expecting.
Yep, that was it right there at 2:54. Bang. Not really even BANG, but more of a bang. There's a bit of a rumble going on for a little while too, but relative to what you hear in period newsreels and at the movies (a prolonged, deafening roar), it seems just slightly, you know, tame.
That said, the quality of the sound before and after the blast makes it easier to absorb the whole experience as much as possible. Also note the time delay: there's about 32 seconds between the flash and the time you hear the explosion, meaning that the guy recording this was set up just over six miles away from ground zero.