I agree with the hunting pressure idea. I also had a basket rack below the stand one morning and was changing the ringer on my phone to vibrate instead of a ring tone. My wife had called and I forgot the vibrate was not on. The buck did not stop eating leaves and look at me. He did not look up when I was whispering either. Very little hunting pressure area though. Same spot I have talked to a jake turkey and had him gobble at my voice as well. These animals see little human pressure to equate with noises and danger together. IMO