When he gives orders to the Mantis Type, he's inside his trailer (or something) where there appears to be a control center of sorts. So it's conceivable there's a microphone there that is used to pick up his orders.
The Mosquito Type, however, appears to just act on its own, and I don't remember seeing Baba speaking any orders to it on any episode.
As for the Great Dane Types, we see him shouting orders, but then near the end of the episode, Wannai almost drowns Baba by surrounding his whole head with water — and it doesn't look like Baba speaks, but instead thinks something like "Great Dane Types, absorb this water," which springs the dogs to action.
How does Baba control and communicate with his robots?
Does he need to speak orders out loud, or is there some sort of mental communication happening?