It was quite loud in the Chaos Compendium. Heart and Mind were fighting again, and Soul was trying to resolve it.

Heart: I'm not a baby! I'm tougher than you think! Mind: Oh, really? You're stupid, and emotional. That's what a baby is. You're not being logical. Soul was getting really annoyed to the point where he had to step in to resolve this. Soul: Can you two just stop fighting? You're both giving me a headache, and you've been arguing for hours!