The Audio Secrets of BioShock

GameSpy is offering up some coverage of a GDC session in which BioShock sound designer Patrick Balthrop revealed how the team created the game’s sound effects and voiceovers.

Patrick Balthrop, 2K’s senior sound designer for BioShock, presented the game’s audio post-mortem. He addressed the specifics of how the team crafted BioShock’s soundscape, which was just as important to its atmosphere as its visuals (point in fact, BioShock won the GDC award for Best Audio this year). The first challenge was with the audio logs and short-wave radios.

In order to create the “sound” of these powerful but archaic devices, the team applied a wealth of post-production. Distortion, down-sampling, gating, and mid-band EQs all helped create the “old-time radio” sound. From there, the team had to create a solution to ensure that the audio could be clearly heard at all times. The player had to be able to hear key information even in the midst of a firefight. Initially, after tagging the logs and radios, the team applied a low-pass filter. That resulted in muddy sound, so instead (using the same tags), the overall mix volume is lowered when a radio or log plays. You’re probably already familiar with the effect from when the whole game suddenly gets quieter as you focus on a dead resident’s confession.

The next challenge was the need for voiceover that brought the AI of Rapture to life. Eventually the team decided on a high limit of three simultaneous speech events, to avoid “cacophony.” They also kept a five-second delay between queued speech events. A simple example of the organization of a speech events parameters (queue, priority, trigger chance, minimum time between events) might be the Little Sister and Big Daddy voiceover sequence.

In order to bring the ecology of the two iconic BioShock characters to our ears, the team created the following sound flow chart (one of many potential sets): summoned Little Sister (the Big Daddy hitting a wall); summoned Little Sister annoyed (the noise as one angrily arrives at a pipe); exitvent; thankful (“Thank you, Mr. B!”); idle; scream (as you approach too closely); recover; threaten; damage; melee (a sequence of the whale song noises from the Big Daddy); death; and cry (“Mister B! Missstteeer Beee!”). Balthrop pointed out that that the whole sequence’s key factors are that it’s relationship-focused and that it’s dynamic, crafted as the two AI characters interact.