Everyone, I believe that I have solved the case of the Halo 3 Mystery Sound.
Watch "Et Tu, Brute?" again. During the warehouse war, listen to the ping of the Spikers firing and crashing into crates. Now, go back and listen to the Bungie podcast.
Tell me that isn't the mystery sound.
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"Hold fast to dreams, for if dreams die, life is a broken winged bird that cannot fly." - Langston Hughes