The Secret Songs of Insects

Friday, May 25, 2007

Most of us are familiar with the gentle chirping of crickets, or the droning of cicadas, but unfortunately most insects are too quiet for humans to hear. We can sharpen our senses with ultrasonic technology and digital manipulation, but these solutions are a little too pricey for the average joe. Instead, let's look to science for the answer.
An insect's mandibles (the part that makes noise) are made largely of copper. This means that any noise that an insect makes will be combined with the harmonic frequency of copper forming a "resonant image". These harmonic frequencies also serve to mask the insect's sound from human ears - a bug "cloaking" device. In order to remove the masking portion from the sound, we must remove the copper-harmonic components.
The easiest method for removing masking components is called bi-resonant cascading. The concept is simple: by collecting sound through a piece of copper (a penny), and transmitting it through a short length of thread to another piece of copper attached to a microphone, we can remove almost all the copper harmonics. Rather than messing around with spectral analysis and digital superconvolution, we let physics filter the sound for us.

How to set up your own insect recording studio:

Watch Video

Materials: 2 pennies, scotch tape, short length of thread, microphone, container.
I recommend using a glass, as shown in the video, as it tends to focus all of the sound inward toward the penny.

These are a few of the most breathtaking insect songs I've recorded:

Boll WeevilPillbug Earthworm

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Blogger duffytoler said...

Ingenious! Wonderful! Nicely illustrates the hidden beauty of the natural world.

On a related note, this material resonance filtering effect is why vellum and metal are no longer used as speaker cone material. Vellum (made from animal skins) could reproduce the sound of musical instruments well, but damped human speech and sounds made on drum skins. Metal cones reproduced speech, but damped the sound of violin strings and brass instruments. Acoustic engineers were eventually forced to use fragile paper cones as a compromise. A side benefit of this, noted by early radio broadcasters, is that the new cones would damp the sound of shuffling paper used by announcers, newsreaders and actors reading scripts for radio dramas.

1:27 PM  
Blogger Ted said...

since when was the earthworm an insect?

12:19 PM  
Blogger duffytoler said...

Ted - Same as a snake is considered a tetrapod ("four footed"). Phylogeny is based on the concept of a "clade" which is irrespective of a particular organism's adaptation.

12:35 PM  
Blogger Ted said...

but by that stand point we can say that these tests (with good results) could be done with humans

11:16 PM  
Blogger Danny said...

I can attest that the earthworm recording is amazingly accurate, as I once had an earthworm crawl in my ear.

8:23 PM  
Blogger dougE said...

oh noes! my bug exploded!

7:15 PM  

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