How do you use that shout I dont get what it does?
You should have got all three words off the one word wall. They'll cost three dragon souls. I imagine that having all three unlocked means you can throw your voice further.
Then you have to put your cursor on the place that the voice is needed to come from before shouting. If that spot is too far away, the shout turns red and doesn't happen so put the target a little nearer to yourself. This one is a fun shout and is helpful when they don't know where you are. You have to be hidden for it to work.
I love it when you have tough enemies running around hearing your insults and you're picking them off with your bow. A well directed voice throw can put an enemy where you want him for easy shooting. But stay stealthy.