How do I make my ragdolls speak/lipsync?

I want to make my TF2 ragdolls say speach from the game. I heard there’s something you can do to make your ragdolls say pre-written lines.

If this is true, how?

This could help

Try this:
http://www.facepunch.com/threads/561104-NPC-Scene-make-NPCs-talk-and-act!?p=10527184