An Apple image depicting how sounds (as spherical wavefronts) bounce off surfaces in a room

What is Spatial Audio?

And why does it matter for Spatial Computing?

Avi Bar-Zeev
8 min readMar 20, 2024

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I recently read an article that promised to fully explain Spatial Audio. Well, I still have questions, and you may too. So let’s try to explain it from the perspective of a Spatial Computing Experience, whatever that is…

My career has been centered on real-time 3D graphics and what we’ll call Spatial Computing (link to definition). I’ve worked with some amazing audio engineers and designers, including Tom Hollman, who invented THX and other extraordinary things. In fact, some of the best technologists I know came from a career in high-end audio engineering, at the very least because (as they will likely tell you) audio is at least 50% of any rich media experience but often much less than 50% of the budget. It’s true.

So let’s try to translate this complex set of technology into something understandable to mere mortals with ears. We’ll start at the rich media experience itself and work our way backwards to tech.

In fact, let’s start with the case of reality:

Imagine we’re sitting together in a room, two of us on either side of a medium round table. When I speak, you’d expect my voice to seem like it’s coming from my mouth, and vice-versa when you speak to me. It’s only natural.

If my voice seems to come from a box sitting on the table or from a trash can in the corner of the room, you might be modestly confused by my newfound skills in ventriloquism. However, if my voice seems to come from inside your own head (instead of from mine), then you might wonder if we are truly in that room at all.

But that’s exactly what happens when you listen to calls on a phone that is held up to one ear. Even stereo headphones often sound like the music or voice is playing in or near your head. Without additional measures, your brain interprets the sound as being “internal” to your head.

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Avi Bar-Zeev

XR Pioneer (30+ years), started/helped projects at Microsoft (HoloLens), Apple, Amazon, Keyhole (Google Earth), Linden Lab (Second Life), Disney (VR), XR Guild