Apple has a patent for earphones (via AppleInsider) that pretty ingeniously suits common usage – the headphones described in the document can automatically detect multiple users using one earbud apiece and switch from stereo sound to mono streams, for instance, or deliver completely different audio streams to each.
People share a single headset all the time, which you’ve probably witnessed if you’ve ever used public transit in a busy city before. Apple’s patent would give them a way to either both hear the best possible version of a single track (instead of just the left or right audio channel), or to both listen to a music, podcast or station of their own preference independent of their earbud co-conspirator.
How do the earbuds know they have multiple and not just one wearer? The patent describes the use of multiple sensors to figure out whether they need to operate in single or multi-user mode. these could include strain detectors at the y-joint where the cable splits in two to connect both right and left buds, and even light detectors and capacitive sensors, too, to help detect how the devices are being worn and at what angles.
Apple’s invention was first filed with the USPTO as a patent application back in 2012, and it’s probably not very likely to make it to shipping hardware. But the kernel behind the idea reveals a key way in which Apple’s R&D department works by responding to the ways people are actually using their devices in the real world; there’s no question this would be convenient to have on those inevitable occasions when you’d actually need it.