Loud voices in public are rather noticeable in Japan.
Today some kids were yelling at the ticket gate of a train station, and all the commuters nearby were staring around nervously. It was kind of odd. Of course, it's not such a big train station, but I just ignored it and went on my way to work.
People are pretty quiet inside the trains too. Only rarely are there loud conversations. Half of the time the people talking loudly are foreigners, haha.
Mystery of life: why can't I sit up straight? After a couple minutes I end up slouching in a position that takes as much effort as sitting up straight.