I am hunting Rio's, which are typically pretty vocal birds. If I sit an hour with no gobbles, and no signs of a turkey coming in, I will move...
What I find interesting, is that often, I will walk 50 yards away from where I was sitting and calling, and get a response. I think that a moving hen strikes that reaction...
And, I hunt a canyon with steep sides and I can call and walk without being seen (although I have learned to walk around the bends with a bit more trepidation). Often times I will walk down a mile or so without striking a gobble, and then start hearing birds on the same walk back up...
Although it can be risky, sometimes I think walking and calling can help to instigate a response a bit better... Sometimes it can burn you though, and you will do more harm than good.