I was just playing Skyrim and was on my way up the Throat of the World and the first watching said that the power of the voice could be used to "blot out the sky and flood the land." It would be an interesting angle to go from with this DLC and I know I would enjoy it, but since they need an Elder Scroll in order to do so something tells me this isn't true unless they need the scroll to find the location of the Word Wall to learn this Thu'um.
Just an interesting point I thought I would bring up.
well this actually makes no sense xD, the Elder Scroll is an ancient "thing" that no one understand it's real purpose, it usually is associated with prophecies, but no one understands it's real power, maybe except the Dwemer, but they are dead so it does not count

In Skyrim we used the Elder scrolls to travel in time in a time wound to learn a shout from it's creators, but this is just a use of it, unless bethesda say otherwise, they can do anything that no one know how, or when, or why

q-