To me, the "Silence" refers to the vast, encompassing environs - a thick wall surrounding the three, making no room for them to communicate. All three represent the self -- Anna the hedonistic, Esther the Catholic (the guilted, the conscientious), Johan the observant.
"Calling someone else fat won’t make you any skinnier. Calling someone stupid doesn't make you any smarter. And ruining Regina George’s life definitely didn’t make me any happier. All you can do in life is to try to solve the problems in front of you."