That's why hand-operated friction turkey calls were made, they say. Other hunters manage to use mouth diaphragms, killing a few fired-up gobblers with fair yelps and clucks during the spring mating season. Still others call in off-season competitions and the in-season turkey woods to improve their mouth-calling abilities. They study how they call. Competition caller and turkey hunter Shane Simpson, who shared this video tip, is one of these guys.