One day you might not have to worry about sticking your left and right earbuds in the correct ears. Because researchers have created a clever system that automatically adjusts the stereo mix depending on what side each bud is inserted.
The solution, created by researchers at the Igarashi Design Interfaces Project in Tokyo, is actually quite elegant. One of the headphone's buds is equipped with a proximity sensor pointing in one direction. Depending on which side it's inserted, it will either point towards the back, detecting the ear, or point towards the front, detecting nothing. From there it's easy to tell which side is in which ear.
Combined with a small bit of switching circuity, the earbuds can then ensure the left and right sides of a stereo mix are properly sent to your left and right ears. The researchers even propose running a weak current from one side to the other, so the headphones know when only one is being worn. Which would facilitate features like sending a mono mix to each side when they're being shared, or automatically pausing a track assuming you've removed one side to talk to someone. [New Scientist]