Australorp or Barred Rock quieter?  For us, Australorps.  Our Barred Rocks were some of our noisiest birds, a few summers running.  We only had 3 Australorps and they were all quiet as church mice.  Very calm, too.  I guess it just depends.  The Barred Rocks were from "friends" and McMurray.  The Australorps were from McMurray, a few years ago.  The Brahmas were pretty quiet, too. 
 
My quietest over the years, through a number of hens, are green egg layers, White Chanteclers, and Black Copper Marans (Jeane line, or however you spell it).  Of those, the best layers were the green egg layers, though I haven't done any egg counts on the White Chanteclers that I can remember.
 
We found the Barred Rocks a little more pecky than our other breeds.  (I sound like I am picking on the Barred Rocks ... sorry to Barred Rock lovers ... maybe we just got some weird throwbacks or something.)  The green egg layers should be fine if they are picked up a lot as the progress from chicks to adults, though a few will fly a bit better than the average dual purpose hen.  I am a fan of green egg layers, though, don't get me wrong--a great, sturdy, productive chicken.  Most dual purpose hens will be just fine with children.  The lighter breeds (Hamburgs, Campines, Leghorns), on average, are a little more flighty and less wanting to be handled.
 
YMMV.  Actually, your mileage probably will vary a lot.