Acoustic meta-material: a shape that reflects sound but passes light and air


#1

Originally published at: https://boingboing.net/2019/03/13/exotic-topology.html


#2

The researchers muse that their invention could be used to dampen sound from HVAC systems, drones, MRIs, and other hard-to-manage sources of unpleasant sound and noise pollution.

Apartment walls?


#3

You don’t really want the light (sight) and air (smell) from the next apartment to pass right? :joy:


#4

…and ceilings. My very first thought.


#5

That’s just a peppermint Life Saver!


#6

I want it all.


#7

this material actually reflects the sound back

If this were used on highways, might the highways become too loud to be driven on safely?


#8

Still doesn’t provide a solution for people who cause noise pollution on purpose. Boom boxes in public/cars with overpowered stereos, fireworks on non-holidays, etc.


#9

…this material actualy reflects the sound back.

A lot of materials reflect sound, for example, the inside of a PVC pipe.


#10

Let’s put this stuff in cars so we don’t have to listen to idiots blasting bass thuds at stoplights.


#11

since it’s not turning it into heat but reflecting it… isn’t it just making some other place more noisey?


#12

Think of it as an air permeable sound barrier which does the job of insulating against sound without serving as a water retaining barrier that lets mold grow.

I want to see this on Thingverse or it didn’t happen.


#13

This sounds (HA!) kind of like it filters particular frequencies, not all sound. Maybe somebody with a better grasp of acoustic physics can read the paper and check? (I just skimmed the diagrams for frequency response sorts of things)


#14

I still wish this were real.


(source: xkcd)


#15

I feel like there’s a real possibility here to deploy this to certain sitting presidents and talk show hosts.


#16

Eh, I like this solution:


#17

No more renting out jam room space.


#18

Probably not. We currently use stone for the same goal and it reflects a high percentage as well. The problem with sound reflecting barriers for highways is the area where the barriers end. The neighborhoods there tend to have massive sound problems, which are notably worse than they would have had with no barrier.


#19

Yes, you’re right. The summaries that have been floating around the net are horrible. What the device can do is reflect back “94%” of the energy at a particular frequency back. That’s only -13db of attenuation which is nice, but nothing like what you’d need for sound deadening.

I can’t decide which is more underwhelming, the poor attenuation or the narrow band nature of it. If it worked on a wide range of frequencies there might be use for it. If it blocked better at the one frequency, then there’d be applications for it. But to attenuate so poorly and only at one frequency?

If I had to guess, Cory posted this because it involved 3d printing. On that front, I’ll point out that whomever printed the model shown in the article knows very little about 3d printing as that’s a terrible print.


#20

“Our structure is super lightweight, open, and beautiful. Each piece could be used as a tile or brick to scale up and build a sound-canceling, permeable wall,”

Big…Beautiful…wall…They are clearly trying to cash in on that sweet sweet boarder wall money.