Years ago I would have voted 50% but now I never get fooled. I hunt mostly timber and heavy forest and I can just tell the difference between the two sounds.

If you hear them enough they are really quite different.

I voted 100% because I have yet to be wrong in I cant remember how many years. Don't get me wrong, I ALWAYS look to see what's making the noise but I have yet to turn my head and be surprised at what I see (different from what I thought) maybe one day I will.........then I'll pull up this post and amend my answer.