Mini earphones for personal stereos. They don't make your music listening a private matter, as everyone can hear it; it just means everyone hears an annoying high pitched tch ttcchh ttcchh whizz woo tcchh instead of proper music. Proper old fashioned headphones are better.
I now see people wandering around the streets wearing these.
Then again, my woolly hat has an aluminium foil lining, so who am I to judge?

