Apple is working on ways to improve features like Find My AirPods for users to recover misplaced peripherals, including a concept using a microphone array to detect sounds played by the lost item in order to work out which direction they are in relation to the user.
The Find My AirPods feature is handy for AirPods owners, but it has its limitations when it comes to discovering where they are in a local area. The AirPods have a pinging feature which can play an audible alert, which is potentially useful for finding them in a room or an apartment, but does still require the user to hear it.
A patent application called "Locating Wireless Devices," filed by Apple in September 2017, effectively takes the pinging function and upgrades it, by using multiple microphones on another device, such as an iPhone.
In one embodiment, the AirPods play out a sound at a specific frequency, which can be picked up by the user's device. By using two or more microphones and filtering software, the smartphone could use beamforming to work out the direction where the sound came from, and point the user in that direction.
An advanced version would also take advantage of other sensors on the device to determine its own physical position, then with multiple readings, determine the approximate location of the accessory. The user can then be guided to the spot with a compass-style interface pointing the way.
Using a microphone array gives the proposed system a number of advantages, other than more accurate positioning data. First, the use of filters can minimize or eliminate ambient noise from the audio feed for position detection, something not easily performed by human hearing, especially in noisy environments.
Such a system could also take advantage of areas of the spectrum that human hearing simply cannot hear, enabling the possibility of a silent pinging or, more practically, pinging at a frequency that is uncluttered by other sounds.
For users, aside from quickly locating the object, the proposal could help find items in a noisy environment, or to quietly search without making much noise at all. It would also be beneficial for impaired hearing, who would not be able to use the current pinging system at all.
Apple is known for filing large numbers of patent applications on a regular basis, with many of the concepts not making their way into consumer products. Its appearance at the U.S. Patent and Trademark Office is not a guarantee that it will become a fully-fledged feature soon, if at all.
In this case, however, a lot of the ground work has been laid with the existing pinging system. Apple also includes multiple microphones in the iPhone, used for normal calls and for the speakerphone, so it is plausible to use them in concert to listen out for a specific sound for such a function.