Oh good lord... Last week I went to my mom's town by train. An actual train, which goes fast and far. So, I don't know how the fuck do they put acustic protection to the cars but IT SUCKS SO MUCH. I've gotta record a video so you can HEAR it. What an annoying electric beep that the motor made when it was going full speed. Shit.
I think they may have cut the sound proof material to make the whole train lighter, since its meant to go fast without burning too much fuel.
I think you'll find they are probably quite often empty like that, but you are usually travelling at peak hours ;-) I have been on many a train where I've been the only person, or practically the only one, in the carriage. Standard trains, London Underground - even the New York Subway! That one's kinda scary to be on alone at night!