Obviously we've reached a stalemate. We can't agree on the definition of sound, therefore we cannot argue productively any further.

You've hit the nail on the head, Kingkool. I learned long ago that it is fruitless trying to get people to understand that common definitions don't include that big picture necessary for those definitions to even be meaningful. For whatever it's worth, you are correct in my book. No ear to convert compressed airwaves into auditory nerve impulses? Then no sound. No mind to interpret the nerve impulses? Then no sound.

But if you want to continue trying to reach the kind of entity who calls Schrodinger's Cat (one of the most seminal metaphors in quantum mechanics), "too stupid to contemplate," I leave you to it. Good luck.

If no one is around to hear it fall does it make a sound. Bets gentlemen please. The answer is yes it does, no ifs or buts. There is no human to hear it but I am certain the little mouse that got crushed heard it.

Naughty, naughty. You just rigged the betting by introducing the mouse. For of course a mouse has auditory sensory equipment, so of course the air compression caused by the falling tree creates a sound. How could there not be? Sound is exactly what happens when the auditory sense encounters air compression. Remove the mouse and I'm happy to place my bet on there being no sound.

Be careful I have a time machine and a tape recorder. Now do you want to bet?

Time machines don't exist so I'll ignore that reference (not that I see your point in introducing it anyway). But the tape recorder is fine. Now lets ask the question: If the tree falls and there is no one (or animal with auditory senses like mice) to hear it, did the tree make a sound?

No. It caused compression waves in the surrounding air.

Did the tape recorder record a sound? No. Its microphone generated electrical signals in response to the air compression which the tape head converted into specific magnetic signatures in the molecules coating the tape surface.

But isn't that sound recorded on the tape? It certainly has the potential to be, but it isn't sound yet. First we need loudspeakers which are capable of interpreting the tape's magnetic signatures into patterns of specific electrical voltage variations that can force a speaker membrane to vibrate, reproducing a facsimile of the original compressed airwaves from the falling tree.

Almost there...now all we need is an ear, just like we needed one in the forest without a tape recorder, to convert the airwaves into biochemical neural impulses interpretable by a mind. Voila: sound. So you see, the tape recorder alone isn't gonna do the trick. My bet is still on no sound in the uninhabited forest complete with tape recorder.

So now we are actually saying the air will not be compressed by the effect of a tree falling. An amazing bit of scientific logic here.

I think by now most everyone in these fora are aware of your penchant for non sequiturs, Xris. But if you actually wish to explain how you arrive at such an erroneous conclusion I'll bother to read your reasoning, if you like.

My farts are not smelly if my wife does not smell them. Now that is logical.

Not quite. It's only logical if there is no other nose nearby capable of converting the airborne feces molecules into olfactory neural signals for a mind to interpret as smelly farts.

If our mind isn't expecting a loud noise, why then can we still hear it?

The auditory nerve is under the control of that part of the nervous system called the "autonomic" or involuntary nervous system. It cannot be turned off. If, however, the mind is unconscious such as in deep sleep, the mind may still fail to recognize the nervous impulse. In that case, you still don't have sound, just unprocessed neural energy that quickly dissipates.

To the non-realists ------------- Your spouses or significant others have it made, because they can cheat on you and if you don't SEE it with your own eyes - well - it didn't happen!!

This non-realist recommends that when you get to college, don't pursue a career in analysis.

A tree is not dependant on an observer.

Yes it is. Otherwise it is merely its base quanta, undifferentiated from any other quanta; such differentiation that would objectify the tree being the result of interaction with sensorial (observational) apparata.

There are no experiments indicating that sound is dependant on human ear.

That's the point really. Experiments constitute observation so would record sound by the simple definition of what an experiment is.

It comes down to the fact that through observations a tree falling will make a noise.

That's correct: through observations. I'm glad you concur with me.

Now if you can prove by any means possible a certain tree will not then I am happy to accept your argument.

Sorry, but you're the one claiming the factual existence of an unheard noise, so the burden of proof is on you: Go ahead and prove to me that a tree makes a sound in the absence of aural observation, be it by ear or recorder. I'll listen.

Semantics nonsense to imagine that a human ear is required to appreciate any noise.

No, it's called philosophy.

Since common-language definitions are based in common-sense observation and interpretation, not in philosophical musing, it is disapointing to me when common-sense conclusions are defended as though they represent philosophy. The tree falling in the forest, to me, is a worthy example of the interconnectedness of phenomena since every conceptual component along the path to hearing is required for the sound to exist. Of what philosophical relevance is it that the common definition of sound includes unheard airwaves in the forest? I'm perfectly able to appreciate that the use of the word sound in common usage does cover unheard airwaves but so what? This is a philosophy forum, not an anti-philosophy forum.