If a tree falls in the forest, and no one is around to hear it, does it make a sound? This paradox is the perfect philosophical cliché, often asked but rarely answered. At first glance it feels like the question could be purely one of semantics. How we define the word ‘sound’ determines the answer. We can define sound as a purely auditory phenomenon that only achieves its characteristic features when air waves are funneled into a person’s outer ear canal. This vibrates the person’s tympanic membrane, then her tiny inner ear bones, and then the fluid in her cochlea, which stimulates the basilar membrane of the organ of Corti, and converts the frequency patterns to electronic nerve impulses that her brain interprets as tonal sensations. Sounds are what we experience in our minds, and are thus dependent upon them. If this is how we define sound a tree falling in the forecast doesn’t cause a sound without anyone there to hear it. The falling tree only causes air waves, and to get sound from those requires a mind.
If a slightly different question is asked, the answer is no longer so straightforward though. What if a lost and lonely iPod plays a song in the forest, and no one is around to hear it. Does it make a sound? It is harder to say no this time, because if the air waves being created by the iPod are not sound then they are most certainly not music. On the other hand, how can we say that the iPod is not playing music? The iPod is in point of fact playing back a previously recorded performance of a musical composition. The iPod’s headphone speakers are vibrating in frequency patterns intentionally arranged, with rhythmic, harmonic, and melodic structure in mind. On the iPod’s screen the artist and song are displayed, corresponding to the compression pattern of air waves that it is producing. The iPod indicates that it is playing music, and the fact that there is not a listener there to appreciate it, does not seem to change what the iPod is doing. If an approaching listener, searching for her lost iPod, were to suddenly hear the song it was playing, it would seem strange to say that the iPod was only playing music after its owner came within earshot, but not before. What was she listening for then? Unless objective reality is constructed by perception alone, a problematic proposition all by itself, then it seems that music must be music even when no one is there to hear it. If music is music, then isn’t sound sound?
I am working on an article which I will be posting later in March, called “The Visualization of Sound”, which is a completely absurd notion if sound is only an auditory phenomenon. I don’t think sound is mind dependent, but where do you come down on the question? If a tree falls in the forest, and no one is around to hear it, does it make a sound? Please leave a comment and solve that paradox.
Jared Roy Endicott