I'm definitly no expert, but heres my take on it. Here in the part of Va. where i live and hunt you might as well leave the owl hooters and crow calls at home, IMO. Not sure if it's hunting pressure or what but in 8-10yrs. of trying i've never once gotten a response from either of these calls. The only way i can locate a bird on roost is to find a spot where you can hear well from, such as a ridgetop, wait tillthe grey sky of duskand cutt loud and excitedly 4-5 times and taper down into a series of 4-5 yelps. Be sure it's late enough that he's on roost or you just might have him in your lap. Here again, IMO, the ideal thing is for him to gobble on his own late in the evening, try to pinpoint his location, and sneak in on him before daylight the next morning.
Good Luck!!!