With every vocalization that a wild turkey makes, there can be several variations and each may have different meanings. The "Cluck and Purr" can be soft and subtle, as to convey contentment when a turkey feeds, agression when an upset hen angrily searches out an intruder (may also include "cutts") or may fall somewhere between the two. The hen in the following video gives us a great example of a hen searching out another hen but in a non-threatening manner. When performing a "Cluck and Purr" for an incoming gobbler, it's best to keep it on the subtle side. Too aggressive and the gobbler may mistake your clucks for putts and send him packing.
Video courtesy of Chris Walls