I found these tips on the Hawaii News Now site (ETA : The first link above from Keara)
HOW TO KEEP YOUR ROOSTERS QUIET:
-Black out the bird's cage at night
-Put a muzzle and collar on the bird
-Put a hood or a sock with a hole over the bird's head, and cut out space for the beak and nose
-Soundproof your pens
-Lower the ceiling of the coop after the bird gets on his perch for the night
#1 - Our cockerels crow in the middle of the night
#2 - What kind of muzzle would stop a rooster crowing (while allowing him to eat, drink & breathe?
#3 - Are the beak and nose in a different place on Hawaiian chickens, doesn't a hole for one kinda provide a hole for the other?
#4 - I totally misread the last word and thought 'what good would that do', then I read it again properly and thought 'How?', 'How?' would be appropriate to my original misinterpretation as well.
#5 - What? Has this person had Xzibit 'Pimp their coop' and they have hydraulic lifters in the roof of their coop, and gleaming gold alloys on their chicken tractors
Not meaning to poke fun at the actual article but that just made me laugh. I know only one way to stop a rooster crowing, involving a machete, a block of wood and a barbeque.