We didnt used to have earbuds, we had big clumpy HEADPHONES to listen to music (they were huge, hurt your head, made your hair sweat....the 70's *sigh*)..Anyway, with that loud music in your ears, you yell without realizing it. because its so loud in your ears.
THATS WHY the guy WITH headphones is yelling.
There was a funny movie with Eddy Murphy wearing headphones and singing to the song he was listening to.
......WE couldnt hear the song he was hearing,
just him going " ROXANNE!! YOU DONT HAVE TO TURN ON THE RED LIGHT!!! "
It was hilarious.Because we all made that mistake and embarrassed ourselves a time or two back then (the 80's).