Electromagnetic Fields

            This week’s sound effect is one that you won’t hear all the time.  In fact, rarely at all will you hear it unless you are standing in a massive power plant.  There is a way to record electromagnetic fields that certain electronic components create.  I learned this in another book that I strongly recommend titled Handmade Electronic Music by Nicolas Collins. 

            The device used to record these sounds is actually a piece of ‘spy equipment’ known as a telephone coil.  Its intended use is recording the speaker movement of your telephone to record a call.  It is essentially a guitar pickup, however, consisting of a magnetic core and copper windings.  I have used mine on a few different items, but my favorites have been a 9v DC power supply for my effects pedals and my computers hard drive.  The recording includes both of these.

            The first sound you hear is the power supply.  It is pretty constantly picking up a 60Hz hum that American AC runs at.  The second half of the recording is a hard drive.  It has harmonics to it that kind of give it the sound of a chord being played.  I accidentally had my delay pedal turned on, which is why you can hear a rhythm going on behind it, but I’ve read and found that some of your favorite sounds will come by accident, so I kept it in there, because it was pleasing to me. 

            There are many places and objects that create these magnetic fields, so if you find yourself in possession of one of these telephone coils, make sure you take it around and experiment.