Anti-social
The invention of the Walkman facilitated the end of the social society. Or I’ve read something along those lines, anyway. It is easy to blame some technology, rather than ourselves. Blaming someone else is easier than blaming ourselves. Blaming something inanimate is even easier. Anyway, I like wearing earphones while I’m out and about. It means I can give everyone around me a visual cue that I’m anti-social without all the effort of actually being anti-social. It is a passive form, rather than the aggression of the Loud Person On Phone. You know not to disturb someone with earphones or headphones, if there is someone else nearby to pester who isn’t plugged in. I like that barrier, that shelter.