I just listened to this great interview with John Cage again:
In this interview, Cage claims that sound has no meaning.
I think the question as to if sound has meaning or not relates to the very old philosophical question that if a tree falls in a forest, does it make a sound. If the meaning of sound is that the molecules in the air vibrate when it falls then yes, it makes a sound. If one where to leave a recording device in the forest when the tree fell it would also produce a recording of those vibrations. But if one means by sound what we associate sound with in language, our experience of the sensation of sound, then no, the tree does not make any sound.
It is impossible for us to hear a sound the way a recording device records it. Each time we hear a sound our brains not only filter it, but try to make sense of it. There is a psychological theory refered to as pareidolia