Jamie never mastered the art of being quiet while I train Phoenix. If he can see or hear us, he has an opinion on what we're doing and he's not afraid to share it. I don't know if he thinks we're doing everything wrong or just that he could do it better. He has an incredible range of vocalizations.
This spring I bought a Kibble Nibble. I call it Jamie's Easter egg or his Shut Up toy. It unscrews into two halves and you put food or treats in it and screw it back together. The dog rolls it around until the food falls out through holes on each end. It's like the Buster Cubes, remember those? I think I still have one but darned if I know where it is. This toy is a little nicer because if the dog can't get all the food out, you can unscrew it and clean it out. It doesn't stay in there forever, getting moldy and gross.
When Phoenix and I go out to train at home, half of Jamie's supper goes in his toy. It's not only a toy, it's a timer. By the time he's done smacking it around and has gotten all the food out and starts voicing his opinion on Phoenix's work, I know we've trained for about 20-30 minutes and it's time to quit.