Wow, those are great links, thanks.
For the most part Princess knows the signs for sit, sit pretty, down, come, shake & wait. I'm not sure how well she'd know them if there were never any verbal cues though. My sister told me today that my mom's dogs started barking & Molli turned towards them. Also, my mom clapped & she looked at her. I don't know if that means she can hear loud or just felt the vibrations or even saw it out of the corner of her eye. I've tried calling her, etc, mostly out of habit to get her immediate attention when needed, but I don't yell so I can't really say if that means anything.
She's sweet, but Princess is soooo jealous! She's getting better but we all have to be on alert in case she wants to prove herself.