Tree Falls

In Rational Skepticism someone opened up a discussion on the topic of a tree falling and no one being around to hear it fall.

Goldenmane commented “It's a dumb question dressed up as wisdom.”
    On one hand... Seems to have a point.

On the other hand, I like Ash's answer:
     "dictionary.com wrote:
      Sound:
     1. the sensation produced by stimulation of the organs of hearing by vibrations transmitted through the air or other medium.
     2. mechanical vibrations transmitted through an elastic medium, traveling in air at a speed of approximately 1087 ft. (331 m) per second at sea level.
     Depends on what definition you pick. So the answer is both yes and no!"

Yet Mr. Samsa puts it better:
    "It depends on how you define "sound". If we want to be pedantic about it, sound necessarily requires a 'hearing' thing in order to be classed as sound - however, setting up the thought experiment in this way is still moronic as it relies on semantic ambiguity, rather than demonstrating some interesting quirk of reality. In other words, if a tree falls in a forest it would still create a travelling wave which is what living organisms perceive as sound. It's similar to the situation where someone says, "how many legs does a dog have If we call a tail a leg?" and then, presumably, you say "five" only to be corrected because "Calling a tail a leg does not make it a leg".
    It attempts to use a confusion of category ("what constitutes a sound") to make a counter-intuitive, and incorrect, claim about the "real" world ("it doesn't fit in the category of sound, therefore nothing happens - the falling of the tree is silent"). And it doesn't work that way. Concluding that the tree does not make a "sound" because nobody is there to hear it is doubly ridiculous when you use the same logic against the question. If there is nobody around to hear it, then presumably there is nobody there to see it either, so the tree and the forest don't exist, which means it can't fall nor make a sound. Also, when I sleep at night the entire universe disappears until I wake up again."

To which xrayzed answers:
    “Fortunately there is always somebody else who stays awake to keep it going.
    But imagine what would happen if we all fell asleep at the same time."

Mr. Samsa answers back:
        “Nice try, figment of my imagination, but you disappear when I sleep too. “

xrayzed is unfazed:
        “Your universe that contains me disappears, but my universe that contains you keeps going.
        When I fall asleep my universe that contains you disappears, while your universe that contains me keeps going.
    So it's sort of like juggling, but with realities. It's quite simple if you are prepared to make shit up as you go along.”

Well... Yes, I guess you can go on making shit up as you go along, but I'll stop here.