That is one of the common complaints, that brings people into my office.
What I tell people is: "People always communicate. It's just that sometimes they don't like the message they're getting."
When he sits w/his arms crossed, or rolls his eyes when she speaks, he's communicating plenty: he's closed, he's dismissive, probably because he's angry, and he's hurt.
When she sits at the far end of the couch leaning away from him, she's communicating: "I don't want to be close to you, don't touch me".
Beyond the basics of not making your partner wrong, making 'I' statements, and speaking of your own feelings (and that takes work), effective communication takes skill. That's one of the things I help people with.
