> > When an person, animal, or thing emits a noise, it sends vibrations (sound waves) through the air... [eventually,] nerves carry messages from a bunch of receptors in your ear up to your brain. Your brain then recognizes the sound, or "hears" it, and tells you what you are hearing. The thing you hear is a SOUND.
>
> > So you see, I have to be correct, right?
>
> > ~Den-"do you hear what I hear?"
>
> Your reasoning is absolutely correct (or should I say "absolutely sound"?), to a point. The answer to the question "if a tree falls in a forest, or if a radio plays in a cottage, with nobody around, does it make a sound?" is immediately apparent once you define what a "sound" is. If a "sound" is "vibrations of air molecules", then of course a tree in a forest, or a radio in a cottage, makes a sound regardless of who's there -- the air molecules still vibrate, don't they? On the other hand, if you define a "sound" as "something that is heard" then of course, if nobody hears the radio or the tree falling, then there's no sound. Indeed, there is nothing deep or philosophical about this question; it is entirely semantic.
>
> [...] Often, especially in physics, people consider the vibrations in air by themselves to be "sound". This, as I have stated, is simply a matter of semantics and a measure of the imprecision of the English language. (Britannica.com defines "sound" /both/ as "the sensation perceived by the sense of hearing" as you would have it, and as "mechanical radiant energy that is transmitted by longitudinal pressure waves in a material medium (as air) and is the objective cause of hearing", as your cousin would have it.) So you see, you and your cousin are /both/ right!
>

Taking all factors into consideration, I'd have to side with Den-Kara's cousin. :-) I think I'm forced to go with the physicist's definition of the radio's Sound being "mechanical vibrations of energy as transmitted by pressure waves through the air." That's because even if you physically leave the house -- thereby removing your own "observer status" for subjectively experiencing the radio's sound with your own ears -- you can, nevertheless, assign non-human observers to witness the sound in your absence.

Say, for example, you set up a microphone with a timed tape recorder that reports specific intervals during which the radio was on. When you get back to your house, you play back the tape recorder and objectively verify that the radio did indeed make noise during your absence. A direct human observer to the auditory event is not necessary. This methodology is called deductive inference. We use techniques like this, in our everyday lives, to learn many things about our immediate environment which we ourselves did not (or cannot) directly observe.

Wolfspirit