Reduces the agro range of creatures and eventually causing them to run in fear
Location 1 (Shroud Hearth Barrow)
Shroud Hearth Barrow is next to Ivarstead. if you enter the town and talk to the inn keeper he will mention something about the barrow being haunted. Enter the dungeon and proceed down and kill the guy in ethereal form. Take the book back to the inn keeper who will give you the claw. Proceed back to Shroud Hearth and the shout is (not surprisingly) at the end.