Here are a couple of fun and remarkably simple noise-making projects:
If you saw the second “Crocodile Dundee” movie, you may remember the scene in which the hero swings a flat stick around on the end of a string, which causes it to hum or buzz in a loud and curious way. I was surprised to find that there is nothing special about this, and it is actually quite easy to make this happen with simple materials. All you need to do is to fasten a piece of string to a flat stick, like a tongue depressor. If you swing it rapidly in a circle, the wind will cause the stick to flutter and then spin rapidly around the long axis, which produces a hum.
The picture below shows two of my (successful) attempts to make a bull-roarer. In the end of the tongue depressor pictured below, I whittled a couple of notches and then tied the string in a loop around the notches. In the other “craft stick”, I burned a hole in the end, and tied the string through the hole. Glue would probably work, too. I can make both of these hum, although the tongue depressor is probably the easier of the two.
The third item in the picture is a plastic spoon. In the normal bull-roarer, because it is spinning rapidly, the string tends to get all twisted and coiled and knotted up if you swing for very long. A slightly more elaborate version of the bull-roarer that doesn’t have this problem is a rubber band wrapped around a spoon. In this case, the rubber band sings by vibrating like a guitar string rather than by spinning in circles, so it doesn’t twist up the string. (I have a harder time getting this version to work. I think the most foolproof version of a bull-roarer is the tongue depressor with a thin string.)
Both of the two flat sticks pictured above are commonly available in craft stores and hobby stores, and work quite well. I find that the shape doesn’t make a great deal of difference. In the first stick above, I tried whittling various notches and grooves, thinking that it might make a more complex sound, but it didn’t seem to have much noticeable effect. The sticks do have to be sufficiently broad, however — I tried a thinner popsicle stick, and it didn’t work nearly so well. Also, the string should be fairly thin and allow the stick to spin freely on its axis. Because the sound comes from a rapid spinning motion, if the string binds up and interferes with the motion, that will prevent it from making noise. I also tried a huge piece of cardboard in a similar shape, thinking I would make a louder noise with a bigger device, but the large cardboard didn’t work. The flat noise-making bit has to be heavy enough so that you can work up some speed as you swing it in full fast circles, and not drag through the air like a falling leaf.
I didn’t know what to call these, so I just called them feather-sticks for their resemblance to feathers. These are very simple to make, too, although you have to be able to use a knife. You just whittle one end of a popsicle stick into a thin handle, like this:
Making a thin handle on one end allows you to roll it between your fingers and make it spin around its axis, like the bull-roarer. You can make it spin pretty fast through the air if you place the end between your finger and thumb and then snap your fingers. With a little practice, you can make these sticks fly through the air, spinning rapidly and emitting an odd kind of note as they go. (In this case, the thinner popsicle stick works better than the thicker tongue depressor, probably because it is harder to make the tongue depressor spin fast enough to make noise, although I was able to make both kinds of stick work. The deformity in the pictured popsicle stick probably didn’t help, either.)