I TAed for a group of students who yelled and complained on the first day that they couldn't understand a word their professor was saying. She had the mildest of eastern European accents, and my students were all just being babies. Five weeks into the course I asked them, "Is the accent thing still a problem?" and they all agreed, "Oh, no not at all we got used to it." I will never listen to a student who complains about an accent ever again.