As Rodrigo et. al. have pointed out, the ezdac~ object, by default, turns on audio processing globally. You *can* enable and disable audio in a patcher window, however - you might want to open the ezdac~ help file and look at the tab marked "local" for more on that. But the ezdac~ object isn't intended to turn off audio - there are other alternatives to this, such as the gate~ object.
Have you considered using the "search" feature and then exploring what it gives you while you're patching? It's a good way to learn about using Max.