I’m not an expert, but I think it’s an instinct thing. Of course, I could never experiment with mine because we are surrounded by dozens of roosters (the neighbors raise lots of chickens and they are crowing all day long ).
it's something they naturally do, and some hens that are usually and alpha hen will try to crow on occasion too lol
I had one was hilarious was like he was drunk or something Cocka-hiccup-doodle-hiccup-do
I believe it's instinct, with maybe a bit of mimicking thrown in if the opportunity is there. When my current cockerels first started crowing their cadence was exactly identical to my dominant rooster. As they perfected their crows they each learned to crow differently, so that now no two sound the same.
But in the past I've had single cockerels who learned to crow without ever hearing another rooster. Boys will all crow eventually no matter what