Prior to the internet and social media there was less noise, hence a higher signal to noise ratio.

I presume that holds unless the only "signal" you get is your local priest and feudal lord? Especially since for most of human civilization the vast majority(95%+) couldn't read or write...

Presumably people have gossiped for about as long as they have been able to speak. However, the 'truth content' of the average communication seems very low.

Take something as simple a speed limit sign. That sign is not literally 'true', it simply refers to what the calculation for penalties will be based if you exceed the unstated actual speed limit. Reporting is at best a game of telephone, social media ends up so many hops from what actually happens to be nearly completely separated from reality.

I'm not sure we are talking about the middle ages here.

Hmm. We do get more information, obviously, but I am not sure that means the ratio of true or correct information over false or incorrect information has changed. Formerly, there have been far more myths and lore around that are easier to falsify today, so this goes both ways.

I'm going to disagree with you there. I remember a time when everything written in print was taken as fact. You were treated like a schizophrenic if you suggested a newspaper printed something that wasn't true. Now people routinely fact check from multiple sources.

Sure there may have been more signal to noise ratio, but robber barons had much more influence. Like Bezos and WaPo but EVERY paper.

Truth and information has always been under the control of will. If someone has a "truth", there is a binary decision. The signals have always been under control of he who broadcasts them. The noise doesn't matter, apart from your ability to decide what the most likely truth is for yourself.