The U.S. Patent and Trademark Office today published a patent application filed by Apple in November 2012 (via AppleInsider), detailing a version of Apple's Earbuds that would smartly detect when two users are sharing the same earphone set and in-turn switch audio to single- or multi-user mode.
The headphones would use a variety of sensors, including an "angle sensor configured to measure an angle at the Y-junction of a cable associated with the pair of headphones," to determine in real-time whether the device was being used by more than one person. The Y-junction strain detector would measure the widening gap between the point where the headphones split into buds for the right and left ear, measuring whether to readjust the audio for two users as the gap widens or just one when it stays the same.
Interestingly, the patent also details a possible way that two users would not only be able to listen to the same music with better quality on a single pair of headphones, but listen to completely different songs at the same time. Other options are portrayed in the patent for helping to detect a change between user count, ranging from basic mechanical switches to measuring precise angle alignment of a pair of headphones using light transmission and fiber optic cables.
Given that the patent application was filed over two years ago and Apple has yet to release earphones with the proposed technology, it is unlikely the company has plans to do so. Still, as a response to a common use of one of Apple's products in the wild, today's patent is definitely an interesting glimpse into the way the company observes unexpected uses of even its most simple creations.