My chickens are about 25 feet from my bedroom window. I do not find them that loud at all. I can easily sleep through their crows. Perhaps you just need to get use to it.

There is not much you can do about a rooster crowing. They crow even in coops too. In complete darkness for days on end. They have built in internal clock that still baffles scientist. We don't know why they crow at 4 or 5 AM.

There are "No crowing" collars that look like velcro cable ties. YOU TUBE It. But the birds are only supposed to wear no more than 12 hours a day. So, you put it on them at night and in the morning when most the crowing is should take place you take it off.

The best advice I have for you is to put a fan or something that creates white noise in your room to help cancel the noise.