How can we understand what babies are crying about? Does their cry sound different when they are hungry compared to when they are tired?

Diffeent cries denoted different feelings but i think alot based on experience and gut feelings. I got 4 kids myself and the 1st 2 was considered inexperienced and don't really kn wat they r crying 4. As my #3 & #4 are closer, i grown to understand them better.