Reading in silence

I would like to ask why I am able to concentrate reading a book when there is complete silence, or as well when it is the complete loud chaos - but not in situations inbetween. I managed to isolate my self from the outside world in a constipated train where crying babies and discussing students were evaporating. I managed as well to ignore what was happening in the striking airport sitting on the floor or a busy waiting spot. Or, I was reading listening to the silence of the living room in a winter evening, when no cars drive on the iced road and no birds fly.

Four people reading

I would like to ask what those four people on the tram were reading. They looked like an extract from a movie, wearing similar mantels, the two men also a cap in style, the women also a scarf in color with the jacket. All singularly, sitting on the single seats near the entrance of the tram, aware only of their books and maybe the actual tram stop behind the window near them.