Timber!

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I did write a long, complicated post for this, the second Philosophical Phriday, but it threatened to turn into a book. So here's a nice simple one instead.

If a tree falls in a forest, and no one hears it, does it make a sound? We've all heard the question, and it's not difficult to see that it relies on an ambiguous use of the word "sound".

If sound is defined as longitudinal waves of compression and rarefaction in a medium - specifically, such waves that are capable of creating sympathetic vibrations in the eardrum, then the answer is yes. The tree makes a sound, but no one hears it.

If sound is defined experientally as what a person hears when their brain interprets impulses from their cochleas, fed to it by the eardrum, moving in sympathetic vibration to waves which hit it...then the answer is no. There was no sound because there was no experience of sound.

If you like, you can locate the boundary between "physical signal" and "personal experience" as taking place in various stages - the movement of air inside the ear, the movement of the eardrum, the transmission of this to the cochlea, the reception by the cochlea, the bandwidth splitting that it performs, the reception of "raw" signal by the brain...or the moment where your conscious minds says "Aha! A sound!".

I think where you draw the line (or lines) is largely a matter of taste. The important thing is that the word "sound" has (at least) two senses either side of the line, and conflating them leads to confusion.

In fact, as Wittgenstein was fond of saying, most philosophical questions stem from this kind of carelessness with language.

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This one also threatened to turn into a book, so I've kept what was essentially the preamble, to follow up on the trailing threads in later posts.

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