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Hear and Back Again

Music literally has the power to move us. What we experience as sound is actually an entirely physical phenomenon—a mechanical wave propagated through the air and entering our ears.

fire can be used to visualize sound waves in a rubens’ tube. for more info click here.

Sound begins when a source vibrates, setting surrounding molecules in the air in motion. These particles in turn interact with their nearest neighbors, beginning a sort of collision cascade. As the air molecules bump up against each other, regions of high pressure compressions and low pressure rarefactions form a *pressure wave* as the sound is propagated from one location to another.

In order to hear sound, we must (quite literally) be hit by these pressure waves, which get channeled through our outer ear and crash against our ear drum. The force of impact on the ear drum, which is actually a thin piece of skin stretched over our middle ear, then sets the tiny bones of our middle ear—he hammer, anvil, and stirrup—vibrating at a particular frequency. These vibrations travel to the cochlea of the inner ear, which is lined with roughly 20,000 hair-like nerve cells, each of which is finely tuned to a particular frequency. When the incoming sound’s vibrational frequency matches the native frequency of a particular nerve cell, the cell resonates with a larger amplitude of vibration, releasing an electrical impulse that tells our brains we are hearing something.

But sound waves don’t just magically collapse and funnel straight into our relatively tiny ear openings. These pressure waves interact with everything along their path. So why just think of experiencing music as what happens to your ear and to your brain? It’s hitting your entire body. It’s creeping into every nook and cranny of your surroundings.

Now, imagine your all time favorite song (or a song that you just really really like a lot). For the last decade, mine has been Exit Music (For a Film) by Radiohead. Listening to that song has never been more powerful for me than sitting in my car in some random parking lot and blasting it through the speakers, so my body is completely engulfed by sound. The result has always been some out-of-body//ethereal//floating-like experience. Just like the hair-like nerve cells in our ear are calibrated to react to specific vibrational frequencies, perhaps our bodies are tuned in much the same way so that we are resonating with the songs that most resonate with us.

Of course, our bodies are completely different for one another, so what is moving to me may be just unpleasant noise to you. The beauty of music is that it is so complex; the dynamic range by which we perceive music is far more heterogeneous than how we perceive normal speech for instance. More often than not, music involves the complex interweaving of multiple pitches and timbres, so as it plays it can play us in any one of an infinite number of ways.

Likely because of my biologist-induced fascination with invisible worlds, I wanted to investigate what the mechanical forces that underlie the music that moves me actually look like. To do so, I’ve learned a bit about cymatics, which takes advantage of that fact that sound waves can be visualized as vibrations through a medium like water mixed with corn starch. In collaboration with filmmaker Chelsey Blackmon, i’ve used cymatics to create a video clip of Exit Music (For a Film) to visualize how it feels and sounds at its most powerful.

To get a firmer grasp on what happens as our bodies collide with the sounds around us.