While I was walking into town today, I saw two girls decked out in jogging clothes, and it sounded like they were happily chatting about their day to each other, but had headphones in.
As I got closer, I found that they weren't chatting, they were yelling, even though they're right next to each other. I can only assume that they both had their music playing, and couldn't be bothered pausing it so they could talk in normal volumes to each other.

Even as I walked away from them, they continued yelling at each other about what they've done for the day.