Acoustic Metamaterial Noise Cancellation Device
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- เผยแพร่เมื่อ 25 ก.พ. 2019
- Xin Zhang, Boston University College is Engineering professor of ME, MSE, ECE, BME, and Reza Ghaffarivardavagh, mechanical engineering graduate researcher in Zhang’s lab, have designed an acoustic metamaterial and noise cancellation device capable of blocking up to 94% percent of the transmitted sound energy while preserving air flow.
Read more about this acoustic metamaterial noise cancellation device on BU Research: www.bu.edu/research/articles/... - วิทยาศาสตร์และเทคโนโลยี
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Fantastic! Hopeful to see some earplugs designed with this technology soon. Please put them out on the market for people who suffer with auditory sensitivity.
Sounds like a pure tone...I'd like to hear someone yelling through there
can't wait to see if this is applied in recording / audio engineering setups! awesome work.
So many applications for this technology. Great work! Please get it to market quickly.
Astounding! Congrats everyone for a rather remarkable application. I hope this goes places!
Absolutely amazing!! It could be placed in a car's tailpipe without conventional muffler. The gain in performance and efficiency would be amazing!
I want this in my car exhaust, pc fans, and camper ventilation. Where i can buy it?
There exists countless applications for this tech, kudos!
This will make drone transport more of a reality by reducing the noise!! Wow so many applications BRAVO!
Woah, this is very cool. I was linked here from a misleading article, however, and although it's not your obligation it could be very useful to set people's expectations by providing some more information in the video description about what you need to control in the environment for this to work, such as simplicity of the wave form you can affect. I'm assuming if the acoustic energy is much more chaotic and varied than a higher frequency sin wave that the % of acoustic energy "blocked" will greatly decrease. Thank you for this research and for re-igniting some of my interest in the physics of acoustics! I bet the math was highly satisfying, I used to enjoy calculating simple room modes. Cheers!
Very interesting. Is there any chart to see the attenuation level per frequency? How does the system "work" from 100Hz to 20Hz? Keep up with the good work!
This is really awesome. Great stuff! Kudos.
Insane! And, very cool. The implications of this discovery are endless. (EDIT: The video could've/should've been done in the opposite fashion to show the 'loud' first, then the soft.) Viewers will/should listen to the end, then go back to the beginning to see the full effect.)
That's great! Does it work on general noise or just one pitch?
I need this in my life. In our bathroom van duct specifically, to block the neighbour's fan cross talking.
That is amazing considering the material blocking the sound is actually open. Incredible!
I can def hear the tone before the plug is pulled... I assume that’s the 6% remainder they’re taking about... but what an awesome tech!
Exciting stuff!
Impressive. Does it work for sounds of mixed frequencies or is it tuned just for a specific frequency. Even so, still, very useful in industry where machines, especially electric motors that run at a speficic rpm, and thus emit sound of a specific frequency, could be silenced yet maintain airflow for cooling purposes. Could also be used on car exhausts, possibly. Also, can this model be adapted to work with electromagnetic radiation? Say, around the microwave range?
This is amazing! I wonder what this could be used for! :D
Amazing!!! I want to see math and 3d model. How yo calculate this for my type of noise and how to correct 3d model for it.
For scientific comparison could you build a solid ring with basic materials then test both? I'm curious to see how the acoustic ring changes the sound pattern.
That is remarkable..
I have a question: is it possible to 'stack' a few devices so that an entire range of frequencies are cancelled? even for just a narrow frequency range like the tone in the video such devices are more than welcomed..
Cool stuff! Great work! I need that for my rehearsal studio (and my complaining neighbors!) :)
Wow! Imagine manufacturing plants, machines, and industrial spaces having tuned noise canceling orifices fitted to exhaust, air panels, and around the structure itself. Noise pollution is a real problem!
Wow. That's some nice work. I wouldn't mind experimenting with that in my mixing room. It's already generating discussion amongst sound folks in the post production realm.
QUESTIONS:
1.What is the reflection pattern of these devices ? They might be useful to us studio users as diffusors too, a much easier to build. I would certainly place them across a window to a busy main street in any studio, or shield other people in the house from the sound I produce.
2. What range of frequencies can be thrown back ?
Thanks for sharing.
Can you explain the measurement setup? Why is the measurement being taken at the top of the tube, as opposed to the end of the tube? Any why 2 measurement points? Are these 2 mics being summed or phase correlated in any way? This looks similar to some of the Danley/ EAW designs where certain cutout shapes on a horn are invisible to certain frequencies.
Great development. Can see hundreds of real world applications for everyday use.
GENIAL Y CUANDO ESTARA A LA VENTA EN MEXICO?
Very cool! Is it tuned to only capture certain frequencies, I assume? Or a small spread of frequencies? I assume it can't actually block the entire 20-20khz range of normal audible sound.
Bravo! The commercial implications are almost innumerable.
Amazing!
"94% percent", this broadband frequencies or just at a single frequency, such as 440Hz in this video?
Hmm, it works on a sinewave of a particular wavelength. What they have made is a resonant cavity that is displaced 90 degrees out of phase for the target wavelength (an odd multiple of 1/4 of the wavelength for what sounds to my ears like 500hz. That would be 6 inch spirals more or less). This is not exactly a discovery, at least not to me. This will not work on broadband noise.
Please apply this to retrofit in noisy apartments. This as a building material would change lives throughout the world.
Please publish the info so others can use this too!
I read an article about this metamaterial at Fast Company. My first thought was soundproofing a music listening room, but ...
shaped in such a way that it can catch certain frequencies passing through the air and reflect them back toward their source
Does this mean the music would be reflected back into the room? Also, the term "certain" causes me to wonder if the frequencies affected would be in blocks rather than broad spectrum? So, rather than blocking the entire range of 20 Hz to 20 kHz, only sections of that range would be blocked? Say, 20 Hz to 2.5 kHz and 4 kHz to 4.7 kHz, etc.
Whoa. I've got some USES for this! When can you get this to market - or print instructions so I can 3-D print my own??
Now do the same for range of frequencies or noise and characterize attenuation frequency response... Also in audio we like to use dB, -12.2db (94%) attenuation would be for your device at 460Hz as presented... Link to more info would be helpful.
Awesome !!!
Very cool but what about broadband noise reduction? did it go fine too? The 20-200Hz range seems to be much harder to deal with, right?
12 dB reduction on a pure tone is pretty good. A little better than half as loud. Looking forward to the broadband noise test results.
Had headphones couldn't hear anything. Turned up the volume as you took off the plug. And now I'm officially deff
amazing!
Nice! Would love to see it's behaviour with white/pink noise
cool stuff!
I need this NOW! Just take my money!
is the shape's effectiveness just the helical ramp aspect, or is there something trickier going on inside?
It seems the ring at the end of the pipe caused the sound waves to cancel each other out. This is known as destructive waves. It causes the sound waves to revert back at the proper frequency.
Nice device! When can I put one of these on my airplane's exhaust tip?
It is great. It is effective when touch the object which make the sound. But to prevent pneumatic sound conductor need reseaches more.
May I know how do you manage to synchronize both the mics, we are also making this kind of project and thinking of using logic analyzer, will it work?
This is interesting. Does this operate broadband?
Cool, application could be extremely quiet muffler? I would love to grab the 3D model and play around with it.
How are you guys planning to put these into walls? Will you just have a few hundred of these rings in one wall? Does the ring only work when it's plugged inside a tube? Will it work the same with a flat surface? So many questions
I can't hear you, i have a donut in my mouth.
Why is this haven’t go up to the market yet??????
Any other tests?
With real dynamic sound like music not just one tone?
So what happens when you put the plastic ring up to your ear? What is the bandwidth? Is it designed for only one center frequency?
would love to know how it works!
Dear Boston University, is it possible to get pair of that mufflers? Will be this project open source or already patent pending?
Where can I buy this or something like it? Nobody has a solution that comes even close to this for noisy vents in residential buildings.
Great. Where to buy it? :)
sounded roughly 1000-2500hz -- - Is there any difference of sound dampening capability at different frequencies? A good demonstration would be loud music, for instance, something that is more true to "life-noise" that has a wide range of frequencies
I'm interested in how cheap this material is and how applicable. How expensive would it be to integrate it into my room or my apartment?
Acredito que essa peça seja projeta para a frequência específica que está sendo gerado, para uma aplicação, deveria ver o espectro dos sons gerados e projetar com base neles...
It wont take long before this technology is part of every new airplane manufactured.
Significantly decreased but the tone and frequency can still be heard. I am sure it will be improved after more research.
can someone explain what the metamaterial is. Is that the ring that is removed?
Is the sound source a pure tone? Will the device work as effectively with white noise?
Whats is really important? material or shape?
Works with others materials, with same shape?
Thanks.
Why are you using a sine tone at a very specific frequency instead of just white noise? Isn't it a lot more fair and representative to use some sort of broad-spectrum sound or noise? Otherwise how do you know your results aren't severely biased by some sort of weird resonance issue? My voice singing on the resonance frequency of a bathroom stall gets about 5x louder if I move 2 inches to the left too...
Go ahead, try and say Reza's last name five times fast. But in all seriousness though, this is some pretty cool technology. Really excited to see where this goes.
So, does this device only cut the frequency it is built for? Or does it stop all sound? What would happen with pink noise instead?
maybe a couple of these might help me against my noisy neighbours. I just need to ctick them into my ears. Are small models also possible?
Where is the airflow measurement in this test?
Is this device frequency specific? If you play rock music on the other end, does it reduce the sound by the same percentage?
Nope it blocks out the drummer so now you can hear your favorite song played in a mean guitar solo version! 🤯
So this looks like a factor of 5 reduction = 14 dB correct ? Not bad but whats the resonant length of the pipe ? Not influencing the measurement?
Shouldn't you replace the filter by a similarly sized dummy object for testing? Lengthening and slightly narrowing the tube must change the pitch and volume.
Hi, do you know how to block all the high frequency pollution?
This is sound cancellation, not noise cancellation. It can only cancel out a specific frequency, while noise is a mix of many random frequencies.
where can I buy this silencing material
Does this cancel various frequencies at once?
Great! How to donate for this project??
You guys should post the stl file for hobbyists. If we put these on drones, it would be revolutionary
The bu.edu link isn't working. Can you provide a new one
It is heard that the source generates tonal noise. "Acoustic Metamaterial" dampens the wave with one frequency. Are there results with "white noise"?
What was the initial SPL & Frequency?
That means 12 dB reductions and seems for a single frequency? Am I correct?
Perfectly.
That's not much. But as there is no mechanical obstruction, the solution is quite interesting! It would have been better if they placed the device without obstructing part of the duct
So, how does it fare with broadband noise?
Imagine using this technique to reduce sound in automotive exhaust.
Where can I find the STL? :)
Sounds like you are feeding it a single sine wave. How does it work with a pink noise signal?
Yeah! That´s something I´d like to hear/see.
What frequency range can be blocked?
Does anyone have the scientific article of this experiment?
i wonder how this design will affect horsepower and torque in a forced induction exhaust system.
Cool!
Would be interesting to hear something other than a solid tone.
Where can I buy one of these?
the future
Is this work private? I would like to 3d print or cnc machine one to play around with.