How could Jesus' audience hear Jesus without audio installation?

I am wondering, today we use microphones and large sound systems to amplify someone's speaking. How did they do that 2000 years ago? Jesus spoke outside regularly before large crowds of people. I expect there were enough children, and disagreeing people, so it wasn't always quiet. Your voice won't reach very far when there are a lot of people, especially when there is a kid crying or someone having a discussion. My question is: How did the people back then hear Jesus' (or anyone else) preaching when there was a large crowd?