Nerding out about Spatial Audio
Odd topic, but its one of my favorite tech gadgets, so here goes:
Apple’s Spatial Audio is an extremely underrated technology and is the AR of sound 🧵
What is Spatial Audio?
Simply, it is just surround sound in your AirPods.
But more importantly, it integrates head-tracking to keep space locked as you move around.
This unlocks intriguing applications.
Why does head-tracking matter?
Intuitively, it’s natural for sound to originate from a location. Why should audio sound like its being generated in your ear?
This feels obvious when watching a TV. Sound shouldn’t be at your ear, it should come from all around you.
In order for the AirPods to know which your TV, phone, or iPad is, they track the direction of your head. The AirPods establish this as “forward”.
Even if you look right, the AirPods compensate for your motion and “forward” is held.
However this “forward” will update if it suspects it has changed. This is easier to test in a podcast where forward is arbitrary.
Fun Test: play a podcast. Turn your body 90 degrees, after about 6-8s the soundstage will update what is “forward”.
Hearing the soundstage move around you is very trippy.
Especially fun if you close you eyes and listen carefully. You can literally hear it rotate.
The processing power here is incredible:
- Two separate buds that don’t go out of sync
- Transparency mode blending in outside sound
- Spatializing the audio to create a 3d sound-scape
- Head tracking to maintain “forward”
- Recalibrating “forward” if you change direction
To do all of this in real-time without nauseating users is incredible.
No dropped frames, no distortions. Somehow still 4 hours of listening time in something so small.
Brilliant.