Thanks for the concern Northfork. I will go back with someone for a while until I can assess how aggressive they really are. I keep saying to myself that I want to provoke one into a full visual bluff charge but after this experience not sure my ticker could take that. The gun thing is a quandary for me. The two that did the chest beating thing, or whatever it was, were probably too far away to see that I was wearing one. Once it started raining before the second thing, I had my fleece shirt over the gun to keep it from getting wet. By the time the one did the chuffing thing, I was in the go home mode, it was raining hard, and I had taken the gun off and put it in my truck. I was just standing around hoping to get some audio with the recorder in the truck and unarmed at that point. So maybe that is why the chuffer thought it safe to do his thing. Who knows. But if a gun is displayed will anything happen? I don't know.
I just went through the entire audio tape. Where I think the first chest beating thing, infrasound attempt, or whatever it was, happened the wind was picking up as the rain storm was coming in and the wind noise in the recorder totally covers up anything that happened right then. The rain hit shortly after that, and I covered the recorder up with a baggy to keep it from getting wet. From that point on, you hear a lot of rain on the bag, my footsteps and not much else until I got back to the truck. I may have been walking and not stopped soon enough when the second one happened too. If I am walking my foot steps pretty much cover up anything else. That second one scared me more than the first because it was in behind me and on my way out. I had one flank me one time and know if they are doing that, they using tactics humans used to trap or attack an enemy. It is not passive behavior but something used in an aggressive manner that could be part of an attack. Distract in one direction and while one comes up behind. I did not really plan to do a lot of hiking that day because of a previous knee injury and just wanted to scope out this area more. Normally I would not even go with a chance of ran like that. I carry around about a 1000 worth of camera and recording gear and do not want it to get wet.
Are people hearing the chuffing? My computer has a special audio card so not sure a garden variety computer can play like it does. One guy said it sounds like a crow to him. Sure does not to me. Sounds more like the chuffing thing that Norseman posted with the gorilla. Notice how the pitch goes up and down for each chuff? Sounds sort of like a saw sawing wood only different size pieces of wood with each saw stroke. That sort of rules out bird to me. For me the chuffing experience pretty well nails down ape. That and the chest thumping thing, just does not seem like any human behavior I know of in any primitive culture. Of course what do we know about Neanderthal behavior? They could have beat chest and done all manner of vocalizations to intimidate a stranger.