This article offers a brief explanation of the various 3D sound APIs we list in our reviews, articles and news. ). An API is basically a bunch of instructions that the game developers use to define where the sound should be placed in the 3D space (A3D 1/2/3 and DS3D) or what type of environment you are located in (EAX, I3DL2 and A3D 2/3). Your soundcard, if it supports the API, will then use some clever algorithms to place the sound in 3D space or a reverb algorithm that tries to recreate the sound of the specific environment.

How effectively you will be able to locate the sound depends on the algorithms your soundcard uses, if you use headphones, 2, 4 or 5 speakers and yourself. That is, how well it works is very subjective, particularly when it comes to any virtualized effects.

If your soundcard doesn’t support the API the game may use a software 3D sound/reverb engine or more commonly, stereo panning. The more well known software 3D sound engines available are RSX (part of Miles Sound Systems),  QSound's QMixer and the 3D sound engine part of DS3D. When it comes to reverb engines in games the more well known are the one included with the Unreal engine, the one in Half-Life and the one MS licensed from Creative Labs (not the Audigy or Live reverb engine) that’s part of DirectX8.

The following information has been reproduced courtesy of Chia Chin Lee.  It was originally posted by Chia Chin as a plan update on January 12, 1999 but we thought is was too good to be lost amongst all of the plan updates on the net.  For your information we have included a short biography on Chia Chin Lee taken from Raven Software.

Chia Chin Lee lived in Taiwan, South Africa, France, and Chicago, before graduating as a film major from the University of Wisconsin - Madison.  During college, he became interested in film sound theory after studying the works of sound designer Walter Murch.  He decided to pursue a career that would combine his skills in audio post production and synthesis with his passion for computer games.   Currently working on sound and music at Raven Software, Chia Chin is excited about the future of dynamic audio in computer games.  Credits include Hexen II, Mageslayer, Take No Prisoners, and Hexen II Mission Pack.  He currently is sound designer and composer for Soldier of Fortune.