Apple has recently filed a patent with the United States Patent and Trademark Office titled User Identification Using Headphones, which was spotted by Patently Apple. The patent describes how AirPods can be authenticated by using other nearby devices, ultrasonic signals, voice recognition, and even a wearer's gait. The main concept of the patent is to address the issue that AirPods can't determine if the person wearing it is the authorised user of the device. As Apple explains, this can be an issue since anyone can use the AirPods while connected to a device that belongs to someone else. The connected device is at the risk of releasing personal information, like notification announcements from Siri.
The patent uses a similarity score to verify a user's identity, bypassing the need for Touch ID, Face ID, and any other biometric authentication on any other device. This similarity score is based on a number of variables like the proximity of other nearby devices belonging to the connected device owner.
The company proposes that biometrics can still be used to increase the accuracy of the similarity score and to increase the accuracy of the AirPods, as the patent explains, as well as to receive ultrasonic sounds inside headphones. Variations in the surface of the user's ear canal may cause the ultrasonic signal to reflect off the surface and generate an echo with a signature associated with the user. A user with a larger ear canal may result in an echo having a longer reverberation time than a user with a smaller ear canal.
Apple pointed out that the AirPods can also use information collected by its gyroscopes, accelerometers and microphones about the user's gait to determine whether they are indeed the owners of the connected device.
The company has been known to add new features to its existing AirPods via firmware updates, to include Find My network support, Spatial Audio support, Conversation Boost, and other data points, if it meets the required threshold. It is possible that if Apple does roll out the authentication feature, it will likely come in as an OTA update. This feature is only at the patent stage right now, so there is no knowing if and when Apple will roll this out.