[capt_noonie]

I use two different hand signals. For "speak" I use one or two open hands with palms facing the dog and fingers spread. And I say speak with a low voice almost like a bark myself. This has been easy to teach most of the dogs we've had.

For quiet, what we eventually figured out was when Uni was barking non stop, we would hold out our pointer finger and shake it at her and say no bark, and she eventually would start a low growl instead of a bark. This eventually turned into a trick itself so now she growls on command too.