Apple’s iPhone Will Soon Scan Your Ear to Solve a Big Problem with Spatial Audio
When it comes to digital spatial audio, there’s a limit to how accurate the sense of ‘position’ or ‘3D’ the audio can be without taking into account the unique shape of the user’s head and ears.
Because everybody has a uniquely shaped head, and especially ears, elements of incoming sound from the real world bounce off your head and into your ears in different and very subtle ways
During Apple’s WWDC 2022 keynote, the company announced that iOS 16 will allow users of modern iPhones to scan the shape of their ear to create more accurate spatial audio
Apple is likely to implement this as an HRTF, aka Head-Related Transfer Function. Using an HRTF, digital audio can be modified to replicate the spatial audio cues that are unique to an individual’s ear.
Technology to apply an HRTF in real-time is readily available today, there’s still one big problem that every person needs their own custom HRTF. This involves accurately measuring each ear of each person.
Now Apple says it will make use of advanced sensors in its latest iPhones to allow anyone to scan their head and ears, and create a custom spatial audio profile from that data.
Apple isn’t the first company to offer custom HRTFs based on a computer-vision model of the ear, but having it built into iOS will certainly make the technology much more widespread than it ever has been.
The company hasn’t specifically said this will be based on an HRTF implementation, but it seems highly likely as it’s a known quantity in the spatial audio field.
Ultimately this should result in more accurate digital spatial audio on iPhones (and very likely future Apple XR headsets).
That means that a sound 10 feet from your left ear will sound more like it should at that distance, making it easier to differentiate between a sound 2 feet from your left ear, for instance.
There’s another potential upside to this feature to. If Apple makes it possible for users to download their own custom HRTF profile, they may be able to take it and use it on other devices (like on a VR headset for instance).