Issues with technology

There are a few issues with A3D's advanced features, however. Half Life has very loud footstep sounds, which can be heard distinctly if your opponent is nearby. As with Quake and other games after it, simply knowing the level and listening for the stereo placement and volume of sounds are enough to give you a good idea of where your opponent is. With A3D enabled, this became a much more difficult task. Footsteps were deceivingly muted in some areas and loud in others (due to ubiquitous reflections and occlusions). I couldn't place my opponent's position behind a thick wall because I couldn't hear him. Now of course everyone's saying "Duh, of course you can't, it's more realistic that way." Consider then what happens if you play an opponent without an A3D 2.0-capable sound system. His sound is mapped directly corresponding to your position and distance from him. He can hear you just fine, even if you can't hear him. For the sake of realism, you might be sacrificing a vital asset. This wouldn't be much of a problem if everyone had to play with A3D 2.0, but unfortunately that wouldn't be the case. Toni Schneider acknowledged this, but pointed out that the best thing to do was to model the sound to clue the player in on what his opponent is hiding behind, without actually muting out the sound completely. However, heavily occluding a soft or distant sound is going to make it more difficult to hear, regardless. For an effect that might add a little bit of realism for single player, I don't mind reflections and occlusions at all. For multiplayer competition however, no way am I gonna use it unless everyone else has to also.

As for accurately modeling sounds and environments, one thing I found missing from A3D's list of features was resonance, the "amphitheater" or "megaphone" effect of sound being amplified and carried due to its medium or the design of the structure around it. Hiding under a metal staircase (I hide a lot, don't I?), my opponent passing above me resulted in a dampened, occluded sound. I thought it would have been nice to have the sound resonating through the metal appear louder to me. Similarly, if I shot through the small end of a cone-shaped structure, it would have been awesome to have the sound be greatly amplified on the other end. Toni mentioned that they were working on something like that for the next iteration of A3D, where a sound travelling through different mediums would be realistically affected and transferred from environment to environment - specifically for how submerged sounds would appear to someone above water.

As for Creative's recently announced EAX 2.0, the same issues would apply. Interestingly, Creative labeled one of the features of EAX 2.0 as "obstructions," or sounds occluding through objects (presumably characters and non-world entities) as well as walls and solid brushes. This sounds like a natural progression, but it isn't clear whether A3D's occlusions can or cannot handle the same thing. The wavetracing demo included fully dynamic walls, which could easily be considered "objects," and more importantly, the lack of reflections will certainly force workarounds for implementing occlusions.