Please don't call to my already high-pressured PA birds before season. <img src=icon_smile_wink.gif border=0 align=middle>

In my opinion...
More often then not a gobbler knows exactly where the calling is coming from the first time you make a sound. This means that even if you leave the woods after you hear the first gobble the gobbler may well still come to where you were calling. So, like Edward said, when he shows up and doesn't see a hen you're just making things harder for yourself come season.

Just my $.02 worth.