In our house...with an 11 & almost 14yo who fight just about constantly the Chi's are typically unphased by yelling & continue with their play/sleep/etc. LOL Matilda really is afraid of ANY "unbalanced" energy so she will sometimes go hide in a corner & shake if my 11yo (who is our problem child at the moment) gets too out of hand. Otherwise it's just another day of a noisey household.
I don't think anything bad necessarily happens to them for them to not like yelling. (most of hte time) But when a Chi has or is living in a quiet house & something happens that isn't so quiet or the energy level changes it can travel to them & makes them a bit nervous. They are a sensitive breed after all....and as I say they're like little mirrors of ourselves.