Trying to teach my dogs to bark on command, but having a problem...?

When they're sitting in front of you, say "bark" or "speak" in a happy, higher voice and wait. Be patient, and try it again. They may start to get antsy and start to shuffle around. Say "no, bark". They may let out a little "wuff", and that's when you give them praise and a treat. Rewarding the noise helps them understand that the noise they're making is why they're getting the reward. Not just for sitting in front of you. Make sure you have their attention first too. Don't just hear them barking outside and start saying "bark". That does nothing!