3d sound in this context means when you turn your head the sound remains in the same '3d' position(so if the sound was coming from the side and you turn to face it, it now sound like it's coming from ahead), which is important for vr (with headphones). This isn't really possible with a prerecorded video file unless you have a clever player that can do the 3d transformations from the original sound channels, but I'm not aware of any that can do this yet
I suppose this would be pretty difficult with "live" recorded sound. Stereo microphone arrays are a complex business already, AFAIK there's no audio equivalent of the 360 degree cameras they use for recording VR. Microphones simply cannot be made as directional as speakers.
However with a multichannel surround sound recording, panning/fading the tracks dynamically according to head movements is trivial, all games do this. So I guess you would want a file format that placed all the channels in 3D space over time. That's the kind of thing the spat software I linked in the above post does, except it's also doing cutting edge acoustic modelling and so forth. It needs a hefty computer.
Absolutely true what you're saying. That's why we didn't use live audio for this, but all the sounds were made by a sound studio and placed in a virtual room around a head. We just didn't have the budget to record binaural audio, so we're faking it, till we making it :)
Thanks for the comment. This is exactly how we did this, Wemersive made a special player for us (and the sound studio) that takes into account the position of the oculus and transform/pan the sound to the right position in the virtual room.
