3D sound is another illusion we cast at the listener in order to further trick them into believing that our virtually generated world is real. In fact, 3D sound has been used extensively for years in movies, TV, and of course, video games in order to trick the listener into a more immersive experience. In a movie, for instance, the listener is stationary, so 3D sound can be mimicked by setting up multiple speakers. However, in an AR or VR mobile app, the sound needs to come from a single (mono) or double (stereo, headphones) source. Fortunately, numerous smart people figured out how our human ears hear using a technique called binaural sound to map out sounds in 3D. The next diagram goes into a little more detail on how binaural audio works:
3D sound visualized
Since then, we have figured out not only how to record binaural audio, but also how to play it back,...
