1 and 2 appear to contradict each other. So, unless you can say why they don't, how can both be true? You are saying that "sound" has two different meanings. One in which the proposition is true, and the other in which it is false. This is, I suppose, the accepted solution of the problem (or, better, it is supposed to show that the problem really does not exist) but I am dubious. I don't think it is true that "sound" does have those two different meanings. I think it has one meaning: what people hear.

Words do have multiple meanings, you look up sound EX: define:sound - Google Search and you find multiple. I don't understand how you think that one word has only one meaning?

Words do have multiple meanings, of course. And, maybe so does "sound". The question is whether the solution in terms of ambiguity is a satisfactory solution. Is it true that when the forest in uninhabited, the word "sound" means something different than it means when the forest is uninhabited? Why should it not mean the same thing?

Because the circumstances changed to warrant such a shift in the definition. It is up to the individual to say that under "such and such" circumstance, this definition is put in place. Which leads me back to square one... :brickwall:

If a tree fell and no body was there to hear does it make a sound?

It does and doesn't make a sound. The fact is all the possible outcomes is squeezed into one state, PROVIDED an observer is near by will it then collapse into a single outcome.

Hence, both possibilty(or how ever many possibilities) are all equally possible.

Quantum Theory... Let not common sense fool you xD

If a tree falls and there is nobody to hear it does it make a sound?

Some people say that it doesn't because humans defined the vibrations made by "things" sound, and if the humans aren't there then there is nobody to define those vibrations as sound.

But then there are people (like me) who say that it does make a sound because it is logical to think so, due to proof we have that is very easy to understand:

1)If a tree fell right next to you would it make a sound?

Of course it would, so if you think about it logically, if a tree falls and there is nobody there to hear it it is most likely going to make a sound.

2)If us humans defined those vibrations as "sound", than those vibrations are "sound" no mater if humans are there or not. It is just like saying: If there is a carton of milk and there are no people there to call it milk is it milk? Of course it is.

That is my opinion on the forever popular question.

human ego , nothing happens ( in this Universe ) unless we , Humans are involved

Western philosophy can be a waste of time sometimes. However, since Mr. Purplesawdust is expecting me to share my thoughts on this famous "puzzle," I guess I can waste a few seconds.

Given: A tree falls. No one is around to hear it.
Q: Does it make a sound?

A: Scientifically speaking, yes. No matter what it lands on, no matter which way it falls, it's going to make a sound of some kind. It simply can't literally be proven that it made a sound if nobody was there to witness the event and hear it for themselves. I'd make an analogy to compare the situation but... I can't think of a good one. X) lolz.

Anyway, that's my answer.

No one heard the great volcano of Krakatoa in Indonesia blow up.