For a podcast intro, I was asked to design an audio environment sounding like a factory. It's fairly simple, and is only meant to begin painting a mental picture for a few seconds before it gets overpowered by other effects, VO, and the intro music. Sources: Heavy bunker door: <a href="http://www.freesound.org/people/KToppMod/sounds/237757/" rel="nofollow">http://www.freesound.org/people/KToppMod/sounds/237757/</a> -- License: Attribution Rumble: <a href="http://www.freesound.org/people/unfa/sounds/258339/" rel="nofollow">http://www.freesound.org/people/unfa/sounds/258339/</a> -- License: Attribution Steam pipe: <a href="http://www.freesound.org/people/visions68/sounds/278998/" rel="nofollow">http://www.freesound.org/people/visions68/sounds/278998/</a> -- License: Attribution Machinery: <a href="http://www.freesound.org/people/RutgerMuller/sounds/148292/" rel="nofollow">http://www.freesound.org/people/RutgerMuller/sounds/148292/</a> -- License: Creative Commons 0