Thanks for all the input on this topic. What I'm hearing, (which may be different from what's being said), is that while there may be a trend within a breed, individual personality has a BIG influence.
Within my flock, the Omega hen is by far the quietest. She is a BR.
The loudest, and perhaps the most unplesant to hear at all, is the BO. She is the mid-level hen.
The Alpha hen is the most talkative, but generally has a lower volume and a more pleasant sound, even when displeased. She is a BR.
Thanks again for the interesting and civil discussion!