The Stanford Encyclopaedia of Philosophy is an interesting and sophisticated resource. But today, I happened to google into its article on “sounds“, by Roberto Casati <email@example.com> and Jerome Dokic <Jerome.Dokic@ehess.fr> and I became dismayed. It seems to ask the wrong questions and discuss things that just useless and wrong-headed. Here’s where the article lays out what it thinks are the philosophically important questions about sounds:
The main issues which are on the table concern the nature of sounds. Sounds enter the content of auditory perception. But what are they? Are sounds individuals? Are they events? Are they properties of sounding objects? If they are events, what type of event are they? What is the relation between sounds and sounding objects? Temporal and causal features of sounds will be important in deciding these and related questions. However, it turns out that a fruitful way to organize these issues deals with the spatial properties of sounds.
Indeed, the various philosophical pronouncements about the nature of sounds can be rather neatly classified according to the spatial status each of them assigns to sounds. Where are sounds? Are they anywhere?
None of these questions make much sense in the real world. As a physicist and speech researcher, I know what goes on in the world shortly before we perceive a sound:
- Something vibrates.
- It causes the air near it to vibrate.
- The vibration travels through the air as a pressure wave. The wave spreads out in all directions.
- The pressure wave is modified by all objects it passes. Some things reflect parts of the wave, some things absorb parts.
- The wave gets to your ear, and it makes your ear drum vibrate. That causes the oval window of the cochlea to vibrate, which makes the fluid inside vibrate.
- Hair cells are triggered by the vibrations and send nerve impulses up the auditory nerve to the auditory cortex.
- It gets complicated.
Sounds (whatever the philosophers think they are) are the end-result of a complex process that is spread over space and time. For instance, as I hear a car drive by, my perception is caused by:
- Rubber tires unsticking from the rough road surface and bouncing back into shape. These sounds are, of course, made by four tires simultaneously.
- The sound waves bounce around under the car, bounce off the road, and perhaps other cars near by.
- The sound wave diffracts over the top of the noise barrier at the side of the highway, and some of it bends down towards my window.
- It sneaks through the window somehow, leaking through gaps, vibrating the glass, and mostly bouncing back.
- Then it gets to my ear and various perceptual things happen.
So, in making that sound, there are kilograms of rubber, a ton of fast-moving car, maybe 300kg of air, two windowpanes, and my head. It’s a complicated process that involves a lot of stuff. Notably, if any of that stuff changes, the sound will change slightly. Change the car, the windowpanes, the noise barrier, anything.
So we can think about the philosophical questions they ask:
- Are sounds individuals? Depends on exactly what they mean, but the answer isn’t likely to be interesting. If they mean “individual” = “isolated thing”, the sound of the car tires isn’t very isolated from other sounds. Certainly the sounds from the four tires aren’t very isolated from each other. If they mean “individual” as “unique, never duplicated”, then maybe, if we could somehow split the noise we hear into separate sounds, then no two of them would be exactly alike. (If one can measure precisely enough.) But, the process of splitting is pretty artificial.
- Are they events? By “event”, they seem to mean something that has a fairly definite location and time. That description is spread over many cubic meters of space, and it is only localized in time if you artificially chop the sound into individual moments.
- Are they properties of sounding objects? What you hear is a property of the sounding object, the environment, and you. It’s not just a property of the sounding object.
- What is the relation between sounds and sounding objects? Part of it is called acoustics. Most of the time, acoustics gives you a complicated mathematical relationship between the sounding object and the motion of your ears, and it is not something that is easily expressible in words. Trying to express it in terms of words (unless one wishes to be approximate) is a mistake. This is not a question for philosophers any more — the physicists took it over in the mid 1800s.
- Where are sounds? Are they anywhere? These are simply silly questions. Various parts of the process that produces the sound occur in different places. There is no single place. It’s very much like asking “Where is Julius Caesar now?” He’s not in any one region any more: his atoms are scattered and blow with the breezes.
And, then the article sets off to answer these questions. Not surprisingly, it doesn’t get much of anywhere. I’d be embarrassed to have written that article; it was written from the narrow perspective of people who play games with words in order to score points against other philosophers. It’s not really there to help you understand anything. Or, if it was, they forgot to read all the acoustics literature that’s accumulated in the last century or two.