I did not read all the replies but I have to be very careful with my roosters as I am not allowed chickens at all. lol
First they live in my garage but every day one or more go out with the ladies depending on loudness of crow I either allow them to free range with their flock from 11 am till dusk or I put them in the coop with the ladies where thier crow is muffled by the walls of the structure.
If I know I am going to have a rain storm (like last night) I will leave the roo with the ladies overnight. My theory is everyone is inside with the windows shut. I use this same theory with really hot days or snowy ones. On perfect days I bring the ladies to them and don't take the risk since people are out and enjoying the weather with their windows open.
I keep my coop dark until 9 am when the lights go on so they don't start crowing till then also.
Also the leaf blowers are my friend whenever a gardener is around my area blowing leaves I will take my roos out for some outside time since no one can hear them over all that noise. I am actually considering getting a used one and running it for an hour each day just so I can let the boys out more.
Also I just put that fake fir tree strips (the ones used in chain link fences to make them more privet) I ran the fir strips through my fencing and now not only can the neighbors not see into the run once the leaves have all fallen from autumn, but it is helping to muffle the sound as well. it does not look to bad either. I will take some pics tomorrow when it stops raining.
I have also been collecting any free evergreen trees on craigs list so that I may plant them around my coups to help block people from seeing and also to help muffle sound.
it isnt easy but all the carrying around of my roos and handeling of them have made them all VERY nice so there is a plus side. Although I can not wait until I move to a farm area and can have them crow all day and night if they want too