How did large congregations of people hear speeches (i.e. Lincoln’s address, and countless other older speeches) without the use of microphones?
We’ve actually known about audio engineering for quite a while. Understanding that audio waves bounce is why medieval cathedrals were constructed the way they were, to maximize the echo. If everyone agrees to be quiet, the echoes amplify sound.
A really cool American version of this is at the Old South Meeting House in historic Boston. In the 1700s, they were able to understand echoes well enough to come up with a manual amplifier, namely a solid disk over the lectern.
There were almost no machines. A person in a field could yell a message for many KMs.
Everyone at Gettysburg respected Lincoln, so they all shut up.
I’ve forgotten the actual name of the thing, but I once stood as a tourist in the back of an enormous Mormon meeting hall in Salt Lake City and was able to clearly hear a person speaking from the podium in a normal tone of voice without amplification. It was very impressive architecture.
What’s so special about the cheesemakers?
If people are quiet, and there is no traffic or other sources of noise nearby, the voice of a single shouting man can be clearly heard for quite a long way away. In addition the large congregations were usually held at big amphitheaters which are specifically designed to help the sound from the stage carry outwards. The stages usually had reflectors and resonators at strategic places to make this happen. Where there were problems hearing the people speaking they would use megaphones. These are large cones that a speaker could shout into in order for his voice to become louder and more directed so that more people could hear them. Popular speeches would also be written down or memorized so they could be retold. A lot of the people attending political congregations would be campaigners who would go back to their home towns and recite the speech word for word so that even more would be able to hear it.