An insulated coop helps reduce the sound quite a bit (altho in summer, it's not as helpful because windows are open...). If possible, don't let the birds outside till 8 a.m. or after, the generally accepted time for noises like lawn mowers to get in gear. I also start their day out with sunflower and other seeds scattered about which keeps my sweet roo busy for awhile even after he is let out of the coop.
I love the sound of a roo's crow and only wish those with relentlessly barking dogs all over the neighborhood felt the same way.
I think the amount of crowing generally has to do with the individual rooster personality. My BO roo and my RIR rooster crowed minimally.
Also, my hens and roos all free-range all over the farm every day, so they're often too busy doing "stuff" to spend a lot of time crowing. IMHO, the happier the bird and the more space they have and the more they tire themselves out free-ranging, the less they crow. Also, I generally keep few roos which may keep them from feeling competitive with other roos and thus crowing more.
Others may have other opinions on this, but I think free-ranging keep them quieter.
my rooster cut down his crowing when i got rid of the other 2 roosters but he still does it when ever he wants. Sometimes I think hes talking to me. He crows when his best girl gets out or when I pick her up, he crows when i go into HIS coop and mostly he crows when he feels like it. I havent found any way to slow it down but Im in the category of people who think its not a farm without a crowing rooster. If my neighbor complains then I will complain about all the noise they make