The tree thing is an example of a language/definition problem....when I was in college, we had an example in, I believe, "Pragmatism" by Will James....

He told of once being on a camping trip wtih several men, and returning to camp to find them arguing about a squirrel on a tree, whic was trying, as squirrels do, to not be seen and to hide from the men on the other side of the tree.....so, the guys were were arguing about whether , by trying to see the squirrel and running in circles around the tree, they were also going 'around' the squirrel, who was usually fast enough to be always facing them.

So James said it was simply a matter of deciding what YOU meant by 'around'...if you wanted to CALL it 'around' when you had been to N,S,E & W of the squirrel, then sure...if you wanted 'around' to mean ONLY getting behind the squirrel, then no.....

And the tree noise is similar....if all you mean by sound is whether vibrations were caused in the earth and air, sure...if you **MEAN** by sound, is those vibrations being picked up by a human eardrum and transmitted to a brain and interpretated and such...then no......

very many 'hard' questions are dealt with by just asking the question a bit differently