https://www.theverge.com/circuitbreaker/2018/11/9/18078746/apple-patent-over-ear-headphones-reversable-right-left-earcup

Apple’s been rumored to be working on a pair of its own over-ear headphones for a while now, but details on the rumored product have been pretty slim beyond the basic concept. A newly granted patent, titled “System and method for automatic right-left ear detection for headphones,” may hint at what Apple is planning, though. It describes a pair of headphones that would be reversible, automatically adjusting which ear cup is the right or left based on how you put them on, via 9to5Mac.

The patent claims describe a system where each ear cup would have five microphones on it to be used to determine which ear cup is which through a variety of complicated methods involving comparing relative microphone inputs.