BY WILLIAM GURSTELLE
USING THIS “SOUND SUCKER” DEVICE
allows you to experience a curious sensation:
it’s as if sound is not only being blocked, but
actually sucked away from your ear.
The sound sucker works on a narrow range
of frequencies. My testing showed it most
effective a few cycles to either side of 660Hz
(depending on the amount of gelatin), and the
effect is most noticeable in a room with a wide
spectrum of ambient noise frequencies.
Can you explain this acoustic phenomenon?
Or better yet, can you draw a simple diagram?
Share your explanation with us at makezine.
1. Start cookin’.
Prepare the gelatin according to the box
directions. Before it sets, reserve about a
¼ cup of the liquid for the project.
2. Pack your mug.
Pour the ¼ cup of gelatin into the mug.
Place coffee stirrers in the mug, packing it
as densely as possible. When done, it looks
something like the compound eye of an insect.
3. Let it set.
Place the stirrer-packed mug in the refrigerator
until the gelatin sets. The idea is that the
gelatin seals the bottom tip of each stirrer.
Suck Up the Sound
In a place with medium-to-loud ambient noise,
hold the mug next to your ear, tilted sideways
so the opening is facing your ear. If there’s
enough sound in the 660Hz range, you’ll
notice a sudden drop-off in acoustic energy
(noise) when you bring the sound sucker near.
If you have a frequency generator, test a
range of frequencies. Besides the 660Hz tone,
it also attenuates some higher frequencies. ;
MAKE Contributing Editor William Gurstelle is the author of
the Remaking History column on page 170 and DI Y books
including Backyard Ballistics and The Practical Pyromaniac.
YOU WILL NEED
Gelatin dessert mix such as Jell-O, Knox, etc.
Coffee stirrers, plastic, thin, hollow, 5½"
long ( 1 box)
Mug, large, flat-bottomed
Frequency generator (optional) or frequency
generator smart-device app
Bowl, spoon, and measuring cup
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