I understand this idea might not be new, but I've decided to visualize it anyway.
The main idea is to create most comfortable and mobile headphones and audio player combination. Modern technologies provide very small technological process for hardware, so such things as speakers, flash memory, batteries and bluetooth receiver can be quite small to be be integrated in headphones. And controller can be integrated in a simple wristband. As I see it, such headphones can be very cheap too.
Created and rendered in Blender.