Check out the no crow collars online. Extremely inexpensive and they sometimes work to muffle the crows. They aren't inhumane like some of the dog shock collars are known to be.
I'm not allowed roosters here either. But I somehow ended up with a rooster who wakes me up every morning and tries to get in to my chicken coop. He isn't my rooster. I don't know who he belongs to, but I actually enjoy the sound of a rooster crowing.
Hopefully you get used to it, and don't get in trouble. Roosters really get a bad rap, good on you for keeping him!