Talking loudly on phone and to one another

This scene is quite common in buses as well. But in Metro when everybody is quiet and almost no sound is there, there will definitely be one person who will answer the phone calls as if he is sitting in his room. Such people do not care about others at all. Even the most private and weird talks they would do loudly. Also, groups of 2 or more get engaged in conversations as if they are in a cafeteria. At the beginning, some people might take interest in listening to something that is not relevant to them, but there is a limit. Rest of the passengers always get irritated by such people who are fond of conversing loudly irrespective of the place they are at.