Our second cockerel from this batch started crowing around 8 weeks, and he sounded like a kazoo! One of the others just started trying to crow at 15 weeks, so far he just sounds like he’s yelling.
What's the earliest you've heard one of your little cockerels crow? I have a little Serama boy, Sam, who started at two weeks! He'd do the little gearing up to crow, then peep in a crowing cadence, like peep-peep-peep-pee-peeeee! Here is a video of him doing a baby crow when he was about 4...