What is spatialization?
Spatialization is the act of making something relative to the space it is a part of, or within. In our daily lives, everything in the natural world, by default, is spatialized. If a motorbike whizzes past from left to right, we will hear the sound grow from faint to loud from one side to the other. As it passes by, it will become more prominent in the other ear, before fading into the distance once more. If we were to wake up one morning and the world was no longer spatialized, it would be exceptionally weird.
If we can make our video games a little bit more like the real world, our players can become more immersed. Our zombie game would have been a lot more fun if the player could have heard them faintly in the distance and their inhuman wailing grew louder as they drew closer, from one direction or another.
It is probably obvious that the mathematics of spatialization will be complex. How do we calculate how loud a given sound will be in a specific speaker...