Sony has used MWC to introduce a new "dual listening" experience headset it calls the Xperia Ear Duo. The headphones allow users to interact with music, or notifications, at the same time as being able to hear their immediate environment.
https://www.notebookcheck.net/Sony-intros-anti-noise-cancelling-Xperia-Ear-Duo-headphones.286774.0.html
Does it makes noise?!!! ;)
"anti-noise-cancelling": In contrast to noise-cancelling headphones that try to block out sounds from the environment, these headphones are designed to let you hear ambient conversation and sounds.
So your music is more in the background and people don't have to yell or honk for you to hear them.
I wonder if it helps your brain recognize the direction of the source of environmental sounds. If so, that might help to more clearly separate the environmental sounds from headphone sounds. So for example people might be more likely to notice the sound of an actual oncoming train or truck as something from the environment, not just a sound effect in the music.
(It also integrates with phone notifications and messaging, lowering the music for notifications, and receiving your speech to be converted to a response text. I wonder if it has some technology to pick out your voice from the ambient conversations, like correlating sound with the vibrations from your head.)