Not the OP but you get tuned into this pretty quick going through the normal gamut of kid issues. The _worst_ cry I've heard our son do was when he had a double ear infection, it was immediately obvious from the shrill tone that he was in pain and needed to go the doctor. There is also a slightly less desperate one where he's stuck in something (usually leg/arm in the crib, not really stuck but can't yet reason out how to fix the problem).