My Cayuga pair are really very quiet. Thelma has the loud quack, of course, but I have heard her quack maybe 5 times in 9 months. She was TICKED OFF, though... and it was just ONE loud quack for each instance.
Now, Louie gabbles all the time, but it's not loud at all. Thelma will gabble back very very softly, too.
Thelma has been giving me an egg a day for over 2 months, with only a single day break every week or so. However, there wasn't an egg yesterday or the day before.... so I she's either slowing down for the season OR she's hidden it. (A couple have been laid right in the kiddie pool, and several have been - individually - tucked under the lip of the kiddie pool. She doesn't always lay there; sometimes she lays in the front yard by the 40 gallon water trough.