Sound-suppressing silk can create quiet spaces
news.mit.edu
news.mit.edu
The amount of investment in mitigating noise pollution is pretty underwhelming, partly because it's expensive, I think, but largely from ignorance. I tried to get a former general manager to acoustically treat a big obnoxiously echoey open floor space and their solution was to ignore everything I said and buy some annoying white noise generators, which misunderstands the problem we had with the space. Tons of apartment buildings cheap out on isolation in a really tragic way, where the difference to quality of life could be big with only minor adjustments to plans. The most tragic from my experience: when some builder decided to skip putting a real wall between neighboring apartments' bedrooms. Instead there were closets constructed from a single 3/4" layer. That "wall" couldn't stop a snore.
We have been discussing this with my neighbors. We are both committed to eventually pull the trigger to retrofit, but the initial estimate is $70K and one apartment being under heavy construction for months...
Presumably you're doing a shared wall, but having the plumber or electrician out for two jobs is probably cheaper than having them out twice, right? Especially since there will be similarities in the levels of stupid they find in the walls.
1. It requires the occupants to vacate
2. It is expensive
3. It is difficult to estimate the change it would actually provide
A semi recent house hunting trip involved trying to shout between rooms, going outside and banging on pots and pans. Very informal ways of trying to guess.
It's be wonderful if there were some standard ways to assess, that builders could advertise. Figuring out how to make a rating that is both not crazy expensive to assess, and also meaningful enough that consumers place some level of trust in it isnt easy.
But wow, it feels like there has to be visibility into what we get to drive change. And right now there's just so few ways to know what you're getting.
It's probably less this and more (at least in the US) that it's very, very, very hard to find "multi-family" housing that's not soul-crushingly substandard [0], so at some point you just give up and try to do a reasonably good job of balancing "living your damn life" with "not making so much noise as to be enormously obnoxious too often".
[0] It might be true that very few USians have ever lived in a place with actually adequate acoustic insulation... so very few folks even would think to look for it.
Where are you finding these old school restaurants? We need to make lists.
Long ago when Red Robin still had good food, I didn't want to go there because it was loud as all fuck in their restaurants. Now every restaurant is exactly the same.
Wearing earplugs while chewing is a very strange experience.
They went with easy to clean floors and took out the acoustic tiles leaving the ceilings and air handling systems bare and echoic.
In fancy buildings you also had a lot of decorative wood and molding breaking up the sound. And those embossed tin tiles, covered with a few layers of paint.
For a while during covid, a place I would go to on occasion had full-height plexiglass dividers between each booth. It made such a huge difference in noise, I was sad when they got rid of them.
If you go to a nicer restaurant, you will get a quiet table. It's the type of restaurant that matters - not so much acoustic design.
I grew up in São Paulo, Brazil, an extremely noisy city mostly due to traffic: old vehicles, motorbikes with open exhausts, cars honking, noisy trucks passing by residential neighbourhoods, an airport inside the city (with take-off and landing ramps over major residential neighbourhoods, including one I lived at), etc.
Moved to Sweden more than a decade ago and lived in very quiet places here, nowadays right in front of a forest with a couple of lakes nearby, and I simply cannot spend more than a few weeks back in São Paulo after getting used to the quietness. I feel much, much more stressed just existing there, even inside apartments on the 20th floor, even on the "quieter" parts of the city, it's a physical feeling that I do not shake off until I'm back home in Sweden.
One can get "used" to noisy environments but the difference it is to live in quieter areas is really hard to describe, I don't think I can tolerate living in noisy environments after seeing how life is on the other end of the spectrum...
Of course I still can tolerate the noise, since I still live here. I am used to it and, most of the times, I don’t consciously care. But I do appreciate and miss the quietness.
Whenever I got back to the city, I felt overwhelmed.
I ended up living in the city and getting used to the noise again. I made the conscious decision to do so because I felt like I limited myself a lot in the places that were acceptable.
Comfort is it's own prison.
I wonder, though, if there is some kind of gain I miss out on by getting used to discomfort.
Natural noises have a rhythm that doesn’t stress us out and wake us. Methodical.
A busy road can mostly start to blend into white noise. Unless it’s absolute sociopaths honking in residential neighborhoods.
Suburbs though have leaf blowers that your asshole neighbor uses 2 hours before it’s legal to use it.
That noise is inconsistent, and it is the worst sound. Some people just suck though.
Florida. Key West. Protected bird species. The parking lot roosters. Nothing methodical about them.
I've been around a few suburbs in the USA and they aren't quiet to my ears, they sound dead for a lack of a better word. Dead with the odd noise from a car's engine and tyres (usually a pickup truck), lawn mower, leaf blower rushing through it.
Absolute silence is not even natural, it gives me the creeps when I'm in a deafening silent ambient.
Even to this day, one of my best memory of that place is the quietness I could experience by sitting at wheeling chair in the front of the house and the only sound you’d hear would be the wind, birds and sometimes chickens nearby.
Nowadays it isn’t the same sadly, because the city grew enough turn the road at the front much more busy. Now there’s a motorbike or truck passing by every 2 minutes, which spoils the whole experience.
Having less personal space, privacy, nature, etc. are trade-offs for what a city provides if you are into city life. I don't live far away from the city centre but have nature around, depending where you live on Earth it's not mutually exclusive to have access to both.
So the issue is noise, the rest are trade-offs one can make but I'd venture to say that almost absolutely no one would choose "noisy environment" as a preference for their lifestyle.
We don't even need to do anything radical like getting rid of cars. They can be quiet. Just ban loud vehicles. Force the use of quiet tyres on the road. Do not allow modifications that remove silencers etc. to be used on the road. Race tracks already implement a SPL test for cars at the exhaust. It would be dead easy to implement this for road cars. Already you've probably eliminated the need for anything high-tech for most people.
Then, for the next level, we need to keep driving cars out of our living spaces. Considering the bicycle exists, there is no need for people to transport their bodies from the outside of town to the inside at an average speed of less than 15mph[0]. It's insane.
[0] https://www.london.gov.uk/who-we-are/what-london-assembly-do...
If you live in the city, sure. But 99% of the noise I deal with is family members going about their lives. Would love a solution to help prevent sound transfer indoors, so that I can focus (and sleep) better.
For exterior noise the biggest bang for the buck is replacing windows. I had some soundproof windows put onto my previous house and you could close the door on a parade going by and not even know it was happening.
Except for: tractors, harvesters, mopeds, quadbikes, chainsaws, circular saws, nailguns, lawnmowers, leafblowers, snowblowers, diesel generators, motorboats, skijets, snowmobiles.
I moved to a countryside 2 years ago, escaping from city noise. Now, I’m going back (although to the outer, more quiet side of the city) because I’m going mad - lawnmowers, dogs, tractors, diesel generators, dogs, dogs, lawnmowers, dogs, …
EVs are incredibly quiet. (but yes they still honk)
Tires are shockingly loud.
It’s a matter of people wanting it.
And I guess if it can’t be sure it won’t ticket.
For example, most of the churches where I live have a big meeting room underneath their main worship space. This room has curtains to divide it into smaller spaces for a dozen or more different meetings, including Sunday school, where a dozen (often noisy) children might be in each room.
Having curtains that genuinely reduce the noise between the areas would make a huge difference! It would reduce the demand to build new buildings with separate walled rooms that wouldn't be used most of the time.
Adding flexibility of use to larger spaces with a variety of demands is a problem worth solving, even if it's not as big of a problem as motor vehicle noise in large cities.
I live atm in a place not too far from an airport: I see planes at a distance several times a day, big ones.
I cannot hear them: triple-glazed windows everywhere in the apartment. It works.
I hate noise: since forever I assemble (or have the shop assemble for me) PCs that are extremely quiet. Otherwise I will hear it. AMD 7700X CPU in "eco" mode (in the BIOS) and Noctua cooler/fan, Be Quiet! PSU, Be Quiet! tower. No GPU besides the CPU's iGPU (so it's fanless). I cannot hear that thing.
Then I love music. I'll hear that one loose bolt that did detach and is now vibrating in the system ceiling when I listen to music.
Noisy fridge, fans (there's one in one of the toilet), this or that device humming: there are many source of noise inside your place that can be really annoying when your place is quiet.
Besides the triple-glazed windows, the (small) building is well built: no common walls with neighbors on the same floor (it's the stairs and elevator that do separate the apartments). Only 8 apartments. Very smart architecture. Ultra quiet.
> The correct approach is not to invent some high-tech workaround but to go after the source of the problem.
You've never tried a place with properly installed triple-glazed windows: you'll be surprised. I'm not saying cars shouldn't be less noisy but making your living place quieter ain't that complicated: (quality and properly installed) triple-glazed windows and call it a day.
Asked a home building company if they build with concrete (not that you couldn't insulate a wood construction though) and they scoffed saying it would take 15 years to recoup the costs through energy savings... Which doesn't sound that long to me, it's a house not a car
Could you expand on this? Above 20-30mph tire noise is the dominant noise from vehicles [1] and I haven't yet found a reference that shows significant reduction by choice of tires
Personally I think we need to put cars underground - without tunnels we'll be in traffic hell forever[2]. And imagine the quiet.
[1] https://www.fhwa.dot.gov/pavement/sustainability/articles/ti...
[2] Elon Musk
Nope, unless drivers foot the bill entirely. Tunnels are horrendously expensive to build and maintain. Projects like Boston's Big Dig cost billions of dollars, went over budget, and move a smaller number of people than a proper subway train system.
> without tunnels we'll be in traffic hell forever
Also nope. Adding more lanes just induces more traffic demand. We will never solve traffic by building more car infrastructure. We can only solve traffic indirectly - by mixing residential and commercial building, by making streets safe to walk and bike, and by building a world-class mass-transit system.
It depends on where you live. My apartment building is older, built before acoustic norms came into effect. I can hear my neighbor two floors up wake up in the middle of the night to take a pee.
I have 0 issues with traffic or other city noise, even though I like having my windows open and live in Paris, one of the densest cities in the world.
See Not Just Bikes' "Cities Aren't Loud: Cars Are Loud": https://www.youtube.com/watch?v=CTV-wwszGw8
Dyson fans are meant to be quieter, but for a premium.
Recently: https://www.sciencedirect.com/science/article/pii/S016028962...
https://www.nih.gov/news-events/nih-research-matters/air-pol...
It's easy from a technical standpoint but practically impossible from a human one. The vast majority of people simply don't notice or care that some large percentage of vehicles are intentionally modified to be louder than the legal maximum. Police won't enforce it, and most citizens barely register the noise as present, much less a problem.
Banning ICE vehicles altogether may very well be the only thing that actually gets the problem solved, since that actually has more momentum behind it than enforcement of existing noise regulations does.
If 5% of those are overly loud, that's an average of a very loud noise every 3 seconds, and most of them will take somewhere between 5 and 10 seconds to come and finally go away. If you don't think that's large, we have very different noise thresholds.
The hard numbers I'm aware of are about motorcycles, which have much higher rates of illegal modifications than other vehicles. This source documents a bunch of other sources, with estimates ranging from 40-70%:
When Harley-Davidson and other moppet/scooters would be all electric, that would be quitter.
Not that easy, the electric Harley is intentionally louder than the combustion version - because people want them loud.
(I am not a fan of banning in general, but banning noise is fine by me)
You cannot even hear modern ICE cars running unless you are really close to them. My neighbor's garage door opener is louder than his ICE car...
Road noise is tires/air like you mentioned. Not a real way to deal with that.
They are extremely loud, second only to no muffler cars and sport bikes blasting through deserted back roads.
If you live in the woods with trees, they'll sound as loud as the ocean. If you live near the ocean, well that's always loud.
The biggest offenders are:
1. cars/trucks 2. birds 3. airplanes 4. ac units 5. ocean 6. wind with trees
You'd never know trees sound like the ocean if you aren't around trees. Trains are loud but intermittent. And trains don't run very often anymore where I am.
GP is very right. To this day, I know that if I don't go to sleep until ~03:30, I might just as well stay up - when the birds wake and start making noise, I won't be able to sleep at all. Cars, trams, trains, I can tune out. There's something about bird chirps that makes them impossible for my brain to ignore. It's worse than loud snoring.
Unrelated. To the noise but just as obnoxious, They also seem to get a pervasive joy in cutting town in half by parking their trains in the main line running through the middle of the town lengthwise. I understand the rail line was here first and the town grew up along the length of the track, but why they cant park their train on the miles of empty straight track outside of town. It boggles my mind.
As you can imagine, the low frequency attenuation isn't great. But the performance of higher frequency attenuation is pretty good. I think this material would work well for meeting rooms, and perhaps restaurants. Not for recording studios.
Anecdotal example: I'm currently living above a cafe, with an entire floor (with an office in it) between us and them.
When they drag the tables and chairs around, we can hear it easily, because it sets up a vibration through the structure of the building. Took us a long time to realise where the noise came from — it sounds like it comes from above, but the flat above us has been unoccupied on some of the occasions we heard the noise, and we were only able to confirm the real origin by me being outside the cafe watching them while my partner was inside, and with the two of us on a call so we could directly observe that what the cafe staff were doing correlated with the noises he was hearing.
For example, a window is a very obvious thing. Obvious things, we value. A balcony. A garden. These things either exist in some capacity or they do not, and it's easily to mentally check them.
Acoustic treatment is more akin to differences in heat insulation. You notice it, when it's a problem, at best. Or it's a problem that you pay for all the time, but you don't even know how much. If buyers/renters don't value something directly, even if it impacts the negatively, the incentives on the builders end to spent on it are understandably low. It requires regulation to be done properly (which a lot of countries have understood and, hence, regulated).
The main problem is that acoustics are affected by everything within a room because sound from humans and most loudspeakers spreads in a somewhat special fashion. So your acoustics problem is usually:
1. Sound goes everywhere and it is not directed just to the places where ears are. This way the sound waves of me speaking also hits the ceiling in a million places and these reflected signals come at you with varying time delay and mix with the direct signal of my voice. If the surfaces of the room are hard, you will have those sounds bouncing around till they loose energy.
2. On top of that every room has particular frequencies that it resonates with to create resonances that make that specific frequency ring longer or the room seems to suck the energy out of that frequency. These are called the mosal frequencies of the room.
One remedy to 1 is to make big chunks room surfaces absorptive or to put more stuff into the room that scatters the souns waves earlier. So: carpets, special ceilings, curtains, acoustic panels or foam at the walls, etc. Tirns out human flesh is also quite good ar this, so packing the room with people also helps.
Another way to deal with 1 (if you can't touch the architecture) is to emit souns in a very directed manner only to where ears are. Nut that means microphones, a mixer, 5k€ per piece beamforming loudspeakers + personal with enough acoustic knowledge to place them in the right spot and steer the beam in the right way etc.
The room mode thing is almost luxury to treat by that point, but it typically involves changing the room geometry, and building buying specially tuned absorbers that are tuned and measured within the room. Depending on how low you want to go with the frequency of your acoustic treatment these absorbers become big fast and can take a third of the space in a room.
In my experience the main problem is that people building rooms treat acoustics as some afterthought, something expensive that you need to avoid to save money. In fact the planing stage is the cheapest place to improve acoustics. You could for example not decide to make a conference room with pure concrete walls/ceiling and a tiled floor, because any person should be able ro imagine the acoustics of that room.
I had to work in a newly gallery space that had worse acoustics than a church. When I asked the architect about the acoustics and why the delay times don't fit the purpose, the architect said for money reasons they ordered "a better looking car deck". The acoustic treatment of that space will cost way more than if they just hadn't decided on a barren ceiling and pure concrete walls.
The same points go for insulation between rooms. There is no magic here, just physics. If you want insulation you have to put mass between rooms and decouple/dampen their interactions. You either do that from the start by building things correctly or you do that afterwards by building another floating room in your existing room. In both cases you have to inspect painstakingly for acoustic bridges, sometimes a single nail touching the outer wall in the wrong way already bridges enough sound to make it noticable.
We know how to build good sounding and well insulated spaces. People just don't want to pay for it. We know how to reproduce speech in acoustically horrible places, people just don't want to pay for it. Acoustics is perceived as an abstract, high-brow, fancy classical-music-topic. That is, until people perceive how straining bad acoustics can be, then they want sudden magic solutions.
Isn't that exactly why this is a notable discovery?
What I can't imagine is that ever becoming an economically viable option.
What I can imagine is that we get better materials, like that silk, with crazy absorbtion coefficents on a small volume. But those are still going to be magnitudes more expensive than the best acoustic foam you can buy today and those still need to be placed in the right spots by someone who knows what they are doing. And the person responsible for the room needs to be able and willing to shell out the money for both. That ia why in practise we have bad aounding places and strained brains because your brain needs to focus hard on understanding acoustically smeared words.
As I said, this isn't a unsolved problem. It is just that people don't want to pay for the existing solution and many people don't even think about preventing it as they build new stuff as this is not on their radar or treated as a luxury problem.
My solution would be to make the building code requirements when it comes to acoustics and sonic insulation much stricter, especially if the purpose of a room is to talk/listen within it.
I assume it would only have to be on walls adjacent to other rooms, ie not exterior walls? And how did you really know this worked? Did you ever live in a room like that, or try this on someone who reported it helped back to you in some fashion? Thanks for the idea :D !
Then most importantly we'd go around the cracks of the room with a can of foam insulation and seal every hole we could find.
These rooms where pretty quiet. I can't say how much of a difference just the drywall would be, but if I wanted the cheapest way I'd do foam sealing and double drywall. Tearing everything out to replace behind wall insulation would only be something I'd do if there was zero insulation in the walls. I guess you could tell by knocking the walls with your hand. If they sound hollow you'll know. If you have a friend with a sound proofed room ask to walk around and get a feel for the space so you'll know what to aim for.
Drywall is easy to replace though and something more diy-ers should try more often imo!
Don’t make buildings cost more. Stop the noise.
At the very least, you take a muffler off your Harley, you get your Harley taken away.
Jail.
Consequences for antisocial behavior.
Taking the most expensive fiber in the world and then adding gizmos to it is the wrong way
This is one problem that I think is eminently solvable. Virtually nobody wants these vehicles in their community.
The reason the problem persists is because they disappear out of sight and without evidence before anyone can do anything about it. Just as soon as they annoy everyone, they're gone.
(And let's be honest, the police aren't particularly incentivized to pull these people over, given that they're almost by definition selfish assholes who are difficult to deal with.)
One solution I've been daydreaming of is a device that could cheaply and reliably capture video of passing vehicles (detailed enough to read license plates) and assign a loudness rating. The loudest vehicles could be shared to a database, and the data made freely available to whatever agencies are responsible for issuing tickets.
I suspect that with a large enough body of a evidence, the existing laws become much easier to enforce.
Unfortunately, in the US, we already have a problem with "ghost cars". I see plenty of cars in California with no plates, fake temporary tags, plates with the retroreflective material stripped off, covers that block the view of the plate, etc.
So those loud motorbikes are just going to bend their plates out of sight of the cameras.
I’ve lost countless nights of sleep only because neighbors behind the walls had normal meet conversations past 12am. I really try to not be PITA but it’s my wellbeing vs theirs in the end. It’s a rental apartment so some are sympathetic and some are not.
In case you wonder why not ear plugs could help: they don’t work because I can hear my blood flow and heart beat and it’s even worse.
Heavy curtains are the cheapest/easiest way to "sound deaden" a normal room. Their fabric surface area is greater than the bare wall, and the weight helps isolate vibration. Thinner ones will be less effective. Never effective as foam, and no method is as effective as actual mechanical isolation (IE a room suspended in a room)
You want the noise to be indistinct enough that your mind won't focus on it. So avoid a bad fan that has a whiny pitch, that will drive you crazy.
https://www.reddit.com/r/Carpentry/comments/13j7o4u/staggere...
The solution proposed in the article requires a microphone, and would have a tough time dealing with multiple sources.
It basically records the room, then plays the room back via the silk sheet, but out-of-phase. Because it's out of phase, it cancels out.
The thing I saw was just a pane of glass or plastic with large round holes in it to attenuate/dissipate sound waves while allowing significant airflow.
>In that research, they sewed a single strand of piezoelectric fiber into fabric. Piezoelectric materials produce an electrical signal when squeezed or bent. When a nearby noise causes the fabric to vibrate, the piezoelectric fiber converts those vibrations into an electrical signal, which can capture the sound.
Well, that is ... disconcerting. A slightly funny and dystopian future comes to mind of world leaders having to get naked to ensure they're not being spied on by the possibly nation-state-hacked ad-tracker-subsidized clothes.
Basically:
1) put a mic above one person's head, in the headboard or somewhere near there
2) record the room
3) play the room back from the same location, but out of phase
voila! Snoring cancellation.
One unfortunate side effect is that it might be quite loud for other people in the home! Because the cancellation will only work well at a single point in space; get a few feet away and it will sound like TWO people snoring. (The snorer, and the loudspeaker.)
I am still bit sure how well it really works.
> In vibration-mediated suppression mode, the fabric could reduce sound transmission up to 75 percent.
So about 6 dB reduction.
I was referring to this:
> In the other, more surprising technique, the fabric is held still to suppress vibrations that are key to the transmission of sound. This prevents noise from being transmitted through the fabric and quiets the volume beyond. This second approach allows for noise reduction in much larger spaces like rooms or cars.
My only wish is for a fabric that doesn’t involve poor silkworms.