Pretty likely you can hear it from any of the Lakeview rooms though.
I'd believe that if you request either north side, odd numbered room, high floor or south side even numbered room you'll be able to see most or all of the water parade.
If your are in an odd numbered room (meaning you'll be on the inside of the "C" looking out towards the pool and lake), you should be able to see the water parade (and hear it). You can probably see it from the lakeview balconies that end in even numbers as well, though.
Here are some pictures of our view from room 7905 (dedicated 2BR):
(During the daylight hours)
(At night during the water parade...the music is loud and clear)
We might be able to beat your view. This December after dinner at Narccoosse's we were taking the boat back to VWL. We were the only people on the boat. The Electric Water Pageant was coming on to Bay Lake and we were "forced" to wait until it passed. The parade passed right in front of us and stopped for viewing. We saw the entire parade and fireworks from the boat!
When I think about how much I paid for the boat fireworks viewing years ago I realize what a bargain we got.