I use commands to make mine quieter. I state my intent that they will gradually become less, and then I imagine that they do. I just focus my attention on them and they grow quieter as I imagine. They are in my mind, and so I figure my mind can work to silence them. Sometimes I imagine that the voices are getting carried away, and as I imagine it they appear to be getting pulled away. With the imagination many things can work. By imagining that they talk less works too. Just thinking it helps.