I think calling before the season is bad, bad bad. I hunt a lot of different areas. Some far from the road and generally unknown by other hunters. those birds ussually respond well to calls, and I have had some great hunts. I also hunt areas that others"know about" because there are lots of birds in the area. The birds in these areas respond to calls well, (gobble) but almost always hang up at 80 or more yards out. I think they have just seen to many hunters before season when they have come to practice calls. The guys calling move a little, bird spots a man where hen calls were coming from and they wise up. Once in one of these areas I was calling for a young hunter on youth day. We had set up on a bird we had seen in the back corner of a field. We had gone a long way around to call from a direction that was no where near the road. The bird responded and I thought we might have something going. Then we heard a truck driving along the dirt road about 200 yards away. The truck stopped , door closed and we heard a series of hen yelps. The gobbler didn't make a sound. the truck door closed, truck started up and off it drove. That was the last we heard or saw of that tom.
My advise for what it si worth, scout with binoculars during the day. Also use your ears early in the morning when the birds are on the roost. You can move and find a lot of roost sites before season by going out before dawn and moving around. Use locators if you don't hear birds on their own. But walk away from the truck. Those birds can hear a long way off when they are sitting up in those trees.