old people might think those are hear-aid thingies like theirs, and feel some sort of connection with you, maybe
?
well, my experience is quite limited, just a few times people bothered me while listening to music on earphones, but beside buses and trains I listen to music mostly while walking at a pretty fast pace or when I ride my bike, in both situations I wouldn't probably be stopped by people to have a chat in any case... on trains it happened a bunch of times, I usually take out the earphones making an expression that should express in a quite obvious way that they are bothering me, but I always listen what people has to say... maybe that's becuz once I almost died with my earphones on, what they are tryin' to say might save my life.