Sound

Sound in VR is actually pretty complicated. Our ears hear things differently to someone else's ear. Many VR systems do a simple "if it's on the right, it's louder to my right ear" stereo pan (stereo panning), but this isn't really the way that actual sound works. For VR, and the high frame rates that they require, just like our lighting effects skip doing full raytracing, this sound panning is okay.

More sophisticated VR systems would use something called a Head Related Transfer Function (HRTF). An HRTF is how sound changes when you tilt your head. In other words, how does sound "transfer" based on your head? Each person has their own HRTF; it takes into account the shape of their ears, the bone density in their heads, and the size and shape of their nose and mouth cavities. Our ears, coupled with the way we are raised, during which we train our brain, allows us to do amazing things with an HRTF. For example, humans can locate something in three dimensions by only hearing it from two...