The Quiet Protocol

The most effective way to teach "quiet" is to first teach "speak." Put barking on cue by triggering it on purpose — a doorbell recording works well — and marking the bark with a treat.

Now add the off switch. After a bark, say "quiet" and hold a treat near the dog's nose. Most dogs stop barking to sniff it. Mark the silence with "yes" and reward. The dog learns that quiet earns the treat, and both behaviors are under your control.

Then stretch the silence before you mark it: one second, then three, then five, then ten.