Slave to Noise No More

This is way too cool:

Scientists have discovered a shape that blocks all sound–even your co-workers

A team of Boston University researchers recently stuck a loudspeaker into one end of a PVC pipe. They cranked it up loud. What did they hear? Nothing.

…The pipe was actually left open save for a small, 3D-printed ring placed around the rim. That ring cut 94% of the sound blasting from the speaker, enough to make it inaudible to the human ear.

Here’s the ring, which is totally passive:

[Photo: Cydney Scott/Boston University]

It appears that you have to design it for specific frequencies, and the size is likely to be dependent on the frequencies (making it bulky when blocking low frequencies.

But it’s still way too cool.