Binaural recording in Amnesia

[Tayrtahn]

It is definitely possible to implement this type of audio system in a game. You would have two "listener" objects in the world to represent the player's ears. When a sound is made in the game world, both listeners record their distances from the source of the sound - this information is used to slightly offset the playback of the sound in either the left or the right channel. Putting that together wouldn't be unreasonable, though it would definitely require more memory and CPU usage. Most developers opt for graphical improvements instead.

It's starts to get tricky when dealing with longer sounds though. Say you have a character speaking to the player in your game - the player is able to move and look freely while that character is talking. When the character starts speaking from a point to the right of where the player is looking, we measure the distances to the player's virtual ears and delay the playback of bob_speech01.ogg for the left channel by the appropriate amount. But now the player turns to look in the opposite direction. We have to slow the rate (but not the pitch) at which the right channel is playing while speeding up (but still maintaining the same pitch) the left channel. And in order to be convincing, that all has to be very smooth, which requires constant recalculation. Calculating all of that at least once per frame is bound to use up a lot of resources. It'd be cool if sound cards started implementing this themselves to take the load off the CPU.

For now, most games settle for panning the sound between the left and right channels to simulate direction. It's a reasonably good effect, and (at present) upgrading to true binaural sound is not enough of a benefit to justify the processing demand. Ah well.