Raising babies in the prehistoric ages

So the other day my SO and I were talking about how our little girl would NOT stop crying. He then asked one question I have yet to find a legitimate answer to on the internet and in the library.

How did "cavemen" as he put it, keep their children's cries from attracting predators? Even in medieval times how did they keep their young protected, especially when the husband was away at work and women weren't trained in defending themselves?

What are your thoughts on this? Do you think they practiced similar parenting "tricks" that we used today to soothe our children (example: slings, pacis, etc...) do you think the practices we do actually know about (royals using nurses to raise their children instead of the parents raising them, leaving unwanted children out in the cold, etc) is barbaric or a way of keeping their family line pure and it was acceptable back then?