Tag: AirPods

Spatial Audio” and “Dynamic Head Tracking” are two separate things

Ever since Apple brought “Spatial Audio with Dynamic Head Tracking” (emphasis mine) to the AirPods Pro, there has been a lot of conflation between these two distinct features. Recently two Apple experts talked about this with regard to Apple TV. It’s often assumed that Spatial Audio is not possible on Apple TV, because the Apple TV doesn’t have a U1 chip, but this is due to a misunderstanding of what Spatial Audio is.

Spatial Audio mimics having the multiple speakers of a surround sound system by running a 5.1, 7.1, or Atmos audio source through some algorithms to create a binaural audio effect. This is similar to using ear-shaped microphones to capture sound so that when played back on standard headphones, the audio sounds like it’s coming from different directions. Also known as “holophonic sound,” Disney did this at Epcot with an attraction called “Soundsations”:

This is separate from Dynamic Head Tracking, which is what most people seem to think Spatial Audio is. Dynamic Head Tracking is what makes it sound like the audio is coming from the device that is playing the video, even as you turn your head.

Just as it would be possible to have Dynamic Head Tracking without Spatial Audio — basically a flat stereo sound that remained “stationary” while you moved your head — it would be possible to have Spatial Audio without Dynamic Head Tracking.

In fact, for accessibility reasons, you can turn off Dynamic Head Tracking while leaving Spatial Audio on:

By default, spatial audio makes it sound like the audio is coming from your iPhone, even when your head moves. You can change this behavior so that the audio sounds like it’s following your head movement.

What this means is that there seems to be no technological reason that existing Apple TVs couldn’t do Spatial Audio, or that if there is, it’s because they’re not powerful enough to process the surround sound data through the necessary algorithms, which seems unlikely.

Honestly, I don’t know why Apple TV doesn’t support Spatial Audio, but it’s not the lack of a U1 chip.

And as long as I’m talking about Spatial Audio with Dynamic Head Tracking, I’m a bit surprised that things like Apple Fitness+ and Apple Arcade don’t feature them.

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