This is a good question.
asked Jul 05 '12 at 03:15
The short answer is "No." But by itself that is generally worthless... :^)
This is actually a subtle issue because we usually don't need to separate what we are perceiving from the form in which we are perceiving it. Indeed, this is so rarely-used a distinction that most people don't even have the vocabulary for it. (And while it is a seemingly simple and lighthearted question, understanding this distinction will actually arm you with the fundamental answer to the traditional puzzles around the senses which Skeptics have deployed from Greek times to the present to sow confusion!)
Take color, for example: color is the perceptual form in which we grasp certain facts about the molecular structure at the surface of an object, via their causal interaction with light (absorbing some wavelengths while reflecting others). Yes, that's an odd way to put it -- we normally just say that the ball is red. But the redness isn't really in the ball, which becomes evident if you change the lighting or change our eyes (via, say, surgery or strong stimulus), and the experience of redness changes or goes away even as the ball itself stays the same.
Now, this isn't to say that color is subjective! What's really going on is that the deterministic interaction between our perceptual organs and the ball's surface in a context (of lighting, atmosphere) causes us to experience the ball as red. There is no room for feelings and desires here: the ball and it's surface's molecualr structure are what they are independent of us -- and the perceptual experience of those facts as "redness" lies in the deterministic causal relationship between perceiver and perceived.
And the same applies to every sense-modality. To take another example: flavors are the perceptual form in which we experience certain facts about the molecular makeup of the stuff in our mouths. Change our taste-buds (again, say, surgically or by stimulating them strongly) and the flavors we experience can change, even while the material in our mouth stays the same. Notice the parallel with sight and color, above: taste is to flavor as sight is to color.
And finally, the same of course is the case with hearing and sounds: Hearing is to sound, as taste is to flavor, as sight is to color. Sounds are the perceptual form in which we grasp certain kinds of events here on earth. The events of the leaves and branches pushing through the air as the tree topples, the event(s) of the fibers breaking near it's base, and the event of it striking the ground, all cause vibrations in the air which we perceive in the form of sounds -- the sounds we call whooshing, cracking, crashing.
Like with the other senses, the events we perceive in the form of sounds of course happen whether or not anyone is perceiving them (the tree still topples, the vibrations in the air still occur). But because sound is actually a perceptual form -- the product of a relationship between perceiver and perceived -- it can't exist without a listener, any more than there could be a flavor without a taster or a color without a seer.
I recommend Chapter 2 of Dr. Leonard Peikoff's book, Objectivism, and if you're really interested in the technical nitty-gritty there is Dr. David Kelley's The Evidence of the Senses which provides an in-depth treatment of all of this (and more).
Just to make sure no one is confused by the issue of "sound" as something that humans hear, versus "sound" as something that a falling tree produces, it might be helpful to restate the question as follows:
If a tree fell in the forest and no one was there to hear it, would it still produce physical phenomena that humans (if present) would perceive as sound? If so, what is the best term to denote whatever it is that the falling tree produces and man has the capacity to hear?
In ordinary usage, we tend to use the term "sound" to denote both the physical phenomena and our perception of them. But if we ever encounter a philosopher who plays on the difference in order to induce doubts about cognition, then we probably do need different, more precise terminology. (Something like "acoustic vibrations" perhaps.)
It is also worth emphasizing that a falling tree still falls even if no one is there to see it fall.
There may be another sense of this type of question: how can one know that a falling tree still makes "sound" even if no one is present to observe it? That is actually how I understood the question decades ago when I first heard it. (One can know that the tree falls because one can see it laying on the ground after it has fallen, but sound doesn't "hang around" very long for observation after the fact.)
Update: Existence and Identity
Greg has been emphasizing the form-object distinction in response to the following line of comment:
If we continue with the reasoning of the perceptual forms, couldn't we ultimately claim that everything we perceive is not really there, but only in the relationship reality-stimulus-perceiver? Wouldn't that amount to empiricism (which Obj. rejects)?
In addition to form and object, another distinction that I find helpful is the existence-identity distinction. Sense-perception tells us that something exists, but what it is always requires further observation, such as by additional sensory-perceptual data using the same or additional sensory faculties, or, in man, applying conceptual knowledge, possibly aided by man-made observational instruments. Here is how Ayn Rand expressed the existence-identity distinction in ITOE (refer to the topic of "Sensations" in The Ayn Rand Lexicon):
A sensation is a sensation of something, as distinguished from the nothing of the preceding and succeeding moments. A sensation does not tell man what exists, but only that it exists.
To put the issue another way, something has to "be there" in order for it to interact with our sensory-perceptual faculties to produce our awareness of it. If we can't see it, maybe we can at least touch it or bump into it in the dark. And if we want to know more about it than we can learn ourselves through our own direct sight or touch of it (etc.), we can use our concepts.
Greg already mentioned the discussion in OPAR, Chapter 2 regarding the form-object distinction. Refer especially to the subsection titled, "Sensory Qualities as Real" (pp. 44-48):
Now let us consider a further issue relating to sensory form and to the validity of the senses: the metaphysical status of sensory qualities themselves.
The rest of that OPAR subsection elaborates on this point in some detail. (Additional discussion of sense-perception and concepts can be found in How We Know by Harry Binswanger, which I'm still in the process of reading.)