Alaimo: Cycles of sound and life
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Boy, January is slow here in Ridgway, but we are still up from last year and I know it will be coming back around as the days get longer and warmer. This cycle happens every year as the wave of business ebbs and flows. And not only businesses — life itself can have its ups and downs. This past week we had a young man named AJ play here at the Still. AJ is a very talented and bright young lad from Montrose who is studying music at CMU. I got to thinking about how his life is in the ascension of a wave, while just this morning an older homeless transient who, I imagine, could be said to be experiencing a low point in his life, was escorted by the police to a shelter. All of this got me thinking about cycles and that (of course) got me thinking about the science of music and sound.
Try this at home kids. If you have a Slinky handy (and who doesn’t have a Slinky handy) secure one end of it with tape or string to a chair or doorknob then stretch it out holding the other end in your hand. With your free hand pull the Slinky to the side and let go. A wave of Slinky will form and travels down the length of the Slinky to where it is secured — and a return (inverted) wave will come back to your hand. Try this again with the Slinky stretched tighter or looser. The wave will travel faster the tighter it is stretched and if you had a couple of different thicknesses of Slinky handy in your Slinky collection, you would see that the wave travels slower if the Slinky is thicker or heavier. This type of wave is the same exact wave that happens in guitar, piano or violin strings. In the case of the guitar the string is plucked or strummed (like our Slinky), and in the case of the piano it is hit with a hammer. Each of these methods creates a wave that is abrupt and one time. Compare this to the violin where the bow is drawn across the string (yes, you can also pluck a violin string) slipping and sticking to the string many times in a second. That is why the violin will make one note for as long as the bow is run along it without fading while the guitar note and the piano note fade. But in each of these methods it is the length and thickness of the string as well as its tightness that make the sound higher or lower. There is quite a bit more going on but Alan only gives me 800 words.
Now our voices are a bit more like the violin than a piano. Inside the windpipe (trachea) there are two folds of tissue known as the vocal folds. They are attached to the back of the trachea in the shape of a V to a set of cartilages. Muscles moving the cartilages lengthen and stiffen the folds much like a guitar or violin string changes pitch with tightening. By blowing air across those folds vibrations like a violin bow pulled across the string are caused. In the case of an adult male, the plucking of the fold by the air happens about 110 times per second and in the case of a female around 200 times per second. This is why we can ‘hold’ a note like a violin player — that is until our breath runs out. And though our ears hear in a range of around 20 to 20,000 hertz (Hz, or cycles per second) our voices only make useful sounds in a much smaller range (males 85-180 Hz and females 165-255 Hz).
There are also sounds that we cannot hear at all. Doctors use the ultrasound of quartz crystals vibrated between two and 18 million times a second. When sound is produced this way, it goes through different types of tissue, bounces back and an image can be created from the sound. There are also infrasound stations around the world that listen to the vibrations caused by the very rock of the planet itself and tell us about impending earthquakes. Other infrasound of about 17 Hz causes anxiety in people and the Aurora Borealis makes a wave of 0.1 to 0.01 Hz.
So today, I want you to consider cycles — whether 18 million times a second or .01 times a second, whether the changing fortunes of money or the coming and going of spouses and friends. These cycles make up the music that is the symphony of our lives — even if sometimes we may wish we had the sheet music handy so we didn’t have to play it by ear. Happy Science.
Dr. Joe Alaimo is the owner of Ouray Vet and partner of Trail Town Still. The savior of small animals, thirsty people everywhere and a fairly dangerous man with a garlic press.