Thursday, May 31, 2012
All my life I've enjoyed listening to things. As a kid I could identify my dad's logging truck at about 2 miles - this in a town filled with logging trucks, and spent hours learning to mimic our cat and dog (though I usually don't admit to that). Lately I've started paying attention to a few of the ways in which I use sound, and decided to share the following example.
I was driving over Hagwilget bridge today, and the sound wasn't quite right, so I carefully adjusted my speed till the sound of the tires going across the grating of the bridge hit the right frequency. I don't know exactly which frequency, but it's the frequency of the note occupied by the word "it" in The Beatles' song "Hey Jude", when you listen to the line "don't make 'it' bad" - so think of it as a "don't make iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiit" as you go across the bridge.
Now for a moment of truth - the sound that sounds "right" for me, is the sound my car makes going 60km/h. I think it's a good speed, since it is the same note as the speed limit, just an octave higher. If I am ever pulled over, my reply to the officer will be "it sounded like I was doing the right speed," but I'm not sure they'll buy it as a valid excuse. If I were to figure out which note it actually is, I could take the hertz, convert 60km/h into m/s, and determine how many bumps on the bridge, then time my transit time across it at a constant frequency and calculate how many total, but that sounds like a lot of work.
Were I to sit on the grass above the bridge and listen to the other vehicles I could use the sounds they made to estimate their speed. An octave lower - 30km/h - a fifth higher, would be a ration of 3/2 over the lower note, or 45km/h. A 4th higher, or 4/3, would be 40km/h.
This might seem like I'm focusing on pitch a lot, but I don't think that I'm out of the ordinary, I just took the time analyze one way in which I know that I rely on the sound something is making to tell if it is doing what I want it to be. I know that on the highway I rely almost entirely on the pitch of my car to know if I'm going the correct speed. This is the main reason why it's initially difficult to drive somebody else's vehicle - the sound is wrong, so I have to constantly be correcting my speed, and glancing down at the speedometer. Luckily most cars shift around the same rpm so I don't have to adjust for that.
I know that there must be dozens of other small everyday activities in which pitch plays an important role, but I can't think of any more of them at the moment, but I am trying to pay attention. Are they any ways in which you use sound in your day to day lives that you find interesting?