Eli5: What’s the mechanism by which a multitude of voices become LOUDER and can be heard farther, than a lone voice at the same source?

Question

I live close enough to a sports stadium to occasionally hear the roar of the crowd. But that’s just a bunch of individuals all yelling and making various noises. If that were single individual in the same stadium, I wouldn’t be able to hear anything. Do our voices amplify each other somehow, when in a group?

In: 13

Answer 1

Yes, sound energy ‘adds up’ when there are multiple sound sources present. You can have what’s called ‘coherent sources’ which add perfectly (so 2 sources of exactly the same sound = double the sound) and ‘incoherent sources’ that add imperfectly (2 sources playing different sounds = like 1.3x or so).

A whole stadium of people cheering can sum up to be extremely loud.