In order to secure sound effects for Guild Wars 2, the dedicated team at Arena Net wrangled access to a nuclear power plant.
"Our main objective of the day was to get impulse responses to use later as big and very different reverbs," audio director James Ackley explained on the developer's blog.
"The idea of an impulse response is pretty simple: you make noise (a hand clap, starter pistol, tone sweeps) in an appropriate environment, record it, then use software to recreate that space in a reverb plug-in so you can get that specific reverb back whenever you want."
In other words, by visiting the nuclear power plant, Arena Net was able to record sound information which can be used to build surround sound suggesting unusual spaces - analogs of the game's dungeons, for example.
"The reactor building at Satsop had a lot of different types of rooms—some small, some big, and some huge. All of these structures were covered in concrete and metal, which created more big echo and reverb," Ackley said.
"Three of us were able to walk around in there getting some great hit, bang, drag and overall scary sounds. At one point, two of us were waiting for team member Maclaine Diemer to meet back up with us, and we could hear him two floors below us making some incredible sounds. I recorded some really very fun 'ambience' just from that."
The team also visited a 1350 foot tunnel, collecting "tone sweeps, train-bys, monster sounds, and even Maclaine’s best Eddie Van Halen impression on Rob’s guitar".
"The reverb time in the tunnel was 45 seconds at RT90. It felt like the sound was moving slowly past you, then building bass and coming right back past you — it was like nothing I’ve ever heard before," Ackley commented.
You can see a little travelogue of the team's visit below, and some awesome photos through the link above. Guild Wars 2 is due on PC in 2012.