Purrs, like clucks, are usually contentment noises. Turkeys will cluck and purr about happily as they feed. Turkeys also purr loudly when they're angry. Gobblers will purr as they posture before and during a fight. Quiet clucking and purring works well on pressured birds.
Turkeys putt when they're nervous.
A bird that has spotted danger makes agitated putts, and turkeys will sometimes putt while running away. Beginning hunters live in terror of accidentally making the alarm putt, which differs from the cluck only in intensity. Some hunters will putt once loudly on purpose to make a turkey come out of strut and stick his head up for a clear shot. Also known as the whistle, it's a young turkey's attempt at a yelp. The high-pitched series of whistles, sometimes followed by a few yelps, is a very important call in the fall.