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A new way to silence a noisy location?


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Shooting near a busy road?  Lawn work or construction down the street?  Surround the set with a temporary barrier made from this new material and you'll have a silent set even in the noisiest location.

Ok, so back to reality.  That is obviously an unrealistic fantasy, but new research has come up with a way to reduce 94% of sound transmission without impeding airflow.  So maybe we won't be creating temporary silent zones, but a silent leaf blower may now be a real possibility!  Once they can figure out how to adapt this to aviation, hold for plane may actually become a thing of the past!  For now, I'll continue to be a hopeless optimist as the whole set watches me waiting for an all clear so we can get back to work.

 

https://phys.org/news/2019-03-acoustic-metamaterial-cancels.html

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45 minutes ago, Olle Sjostrom said:

That video on the page you posted is funny though. I mean it’s a very simple edit to make. Not that I don’t believe in it, just that that video doesn’t really prove much.. to my ears. 

I doubt they intended the video to be proof.  They did publish a paper with their results in it, which I have not read.

 

24 minutes ago, drpro said:

Sometimes a suitable amount of cash to the lawn care workers provides relief!!

That's true, but outside of our work, how wonderful would it be if these things no longer made noise?  

 

I joked a lot about how much it could make our work better, but really if this tech pans out I see it really as a major breakthrough in quality of life.  I think I will start holding my breath now.

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A few um, minor nits based on their video and the article. The science seems valid for what it does, based on a single wavelength, and I don't think the video is edited. But...

 

1.  The material has to be calculated to reflect one specific frequency. They demo it with a sinewave (sounds like ~450Hz, tho that's by ear). What happens with an actual real-world sound with multiple changing frequencies?

 

2.  What happens with  a wave at the calculated frequency, but rich in harmonics? 

 

3.  How about impulse noises, more common in production, with sharp rise times that reflect a ton of frequencies momentarily?

 

4.  Their demo has the filter at the end of a long pipe. It seems obvious they picked the length so this wave would be at a particular phase when it reaches the filter. 

 

5.  It's at the end of a long pipe. What happens if the sound - even of a single pitch - is being reflected and coming from multiple directions?

 

6.  If they make a [magical, for now] flexible barrier with broadband reflection, what happens when the barrier flexes and catches different parts of the multifrequency wave? 

 

 

 

If they can figure out a way to make it broadband, it could be great for a rigid camera blimp. Or even if they tune the camera to specific frequencies. Of course it would have to let the air flow, and not interfere with the lens. But maybe... honestly, the physics required are way beyond me... I can't see how it could be done.

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