Apple is researching how AirPods can detect movement and position, partly to assist with Spatial Audio, but also to gauge body motion during Fitness+ workouts.
Apple Fitness+ may be an extremely well-produced service, but inescapably, it's online. There isn't really an instructor watching and encouraging you, it just seems like there is.
Consequently, there are only a few ways Apple can tell that you've actually done the workout you've said you have. Apple Watch is the chief way, as it monitors your heart rate during the session, but you could just be panicking a lot about failing to do the exercise.
So in future, there may be more clues for Apple Fitness+ to interpret, data that can't be fooled by your excessive caffeine intake. "Wireless Ear Bud System With Pose Detection," is a newly-revealed patent application that proposes determining details of your movement via AirPods.
"Ear buds may have sensors to gather orientation information such as accelerometer measurements during user movements," says the patent application. "A host electronic device may communicate wirelessly with the ear buds and may form part of an ear bud system that supplies the user with coaching and feedback while evaluating user performance of a head movement routine or other exercise routine."
It has to be pretty fine measurements to register when, say, an Apple Fitness+ trainer has told you to raise your right arm high over your head. But Apple proposes that any deviation from a starting position, or any deviation from a "fixed orientation to the earth," could help.
"During operation, the ear buds may gather accelerometer data... and may use a rotation matrix," it continues. "The data in the neutral reference frame may be analyzed using a user head pose look-up table to categorize measured user head positions as corresponding to respective user head poses."
So someone at the Apple Fitness center in Los Angeles may even now be working through a catalog of head movements while being recorded. Turn left, turn right, stretching, these could all be compiled into a reference table, as could head-jerks-in-dismay.
There is definitely an aspect to this patent application that could apply to Spatial Audio, with precise changes to audio being made as the user turns their head or moves their body. However, Apple isn't done with the fitness aspect yet.
"Feedback such as audible feedback may be provided to a user based on evaluation of user performance of the head movement routine," it says. "Other suitable actions may be taken such as issuing performance reports and alerts."
So in theory, Apple Fitness+ coaches could record any number of critical comments about your performance, and the AirPods would play them as appropriate.
Fortunately, Apple's patent application does throw in the fact that all of this can be done "if desired."