Bantam breeds are on the smaller scale as chickens go but I bet the can belt out a fairly loud crow when they mature. I know my white rock when he was young he had no volume at all. Now he is over a year old and is a 12 pound veritable crowing machine. With the coop closed up tight in the middle of winter with snow on the ground he still cant be muffled. I think he begins at his toes to get a crow going. So yes they get louder. For all the noise he makes he is an excellent watch dog,lets you know when all is not right with his world. Dont matter what it is,strange car in the d-way,someone walking in the road past the house,squirel doing what they do he lets you know.