Scientists say you can cancel the noise but keep your window open(nytimes.com)
nytimes.com
Scientists say you can cancel the noise but keep your window open
https://www.nytimes.com/2020/07/11/science/windows-street-noise.html
272 comments
I’ve lived in a few apartments that were situated along busy roads. Something like this would be nice, but I’m hopeful that we’ll someday get to a point where (almost) all of the vehicles on our roads will be electric. Has anybody worked out how much of a noise reduction we can expect from that?
EVs will require a mind change. I have a hybrid. I drive it in St Augustine FL, America’s oldest city. As such the roads in the historic district are narrow.
When I come to an intersection I have to be especially conscientious because pedestrians are use to engine noise bouncing down the road ahead of the car. People have walked out in front of me unaware of my existence. I normally mouth, “Surprise, motha fucka” or “I’m Batman” when that happens.
When I come to an intersection I have to be especially conscientious because pedestrians are use to engine noise bouncing down the road ahead of the car. People have walked out in front of me unaware of my existence. I normally mouth, “Surprise, motha fucka” or “I’m Batman” when that happens.
In the US, EVs and hybrids will be required (I'm unclear on the details from the articles I've seen though) to emit artificial noise under 18.6 mph by Sept 2020, and in the EU, under 15 mph by July 2021. [0] Hopefully that will help some, but I'm not excited for the first wave of noises. I'm betting a few are going to be really annoying.
[0] https://www.theverge.com/2019/7/1/20676854/electric-cars-art...
[0] https://www.theverge.com/2019/7/1/20676854/electric-cars-art...
I'm looking forward to it. I use hearing when coming up on intersections in my neighborhood and on a bicycle. The visibility is terrible. I'm never at risk of being run over, but it always shocks me pretty good to see a car coming towards the intersection without a sound. I can hear up to 19khz so I usually hear the batteries/motors, but not all cars make that sound.
I empathize with this viewpoint, but I can't understate how strongly I oppose this idea. Road noise is extremely unpleasant! If somehow the electric motor vehicle had been invented first instead of the ICE there is no way anybody would have proposed that we make them artificially louder... we can put other, much more effective traffic safety measures in place.
I too enjoy cycling and understand that there are serious safety problems involved with cars and bikes sharing the road and that and most of our cities have done a poor job of dealing with them. I don't think keeping around legacy noise pollution is the answer. It reminds me of this: https://xkcd.com/1172/
I too enjoy cycling and understand that there are serious safety problems involved with cars and bikes sharing the road and that and most of our cities have done a poor job of dealing with them. I don't think keeping around legacy noise pollution is the answer. It reminds me of this: https://xkcd.com/1172/
> we can put other, much more effective traffic safety measures in place.
Like? (Don't limit yourself to the easy-to-introduce-today; not everywhere has established road infrastructure, and your ideas could be used there.)
Like? (Don't limit yourself to the easy-to-introduce-today; not everywhere has established road infrastructure, and your ideas could be used there.)
Anything louder than "silent" is good, but it need not be nearly as loud as an ICE engine.
> Road noise is extremely unpleasant
We have to stop treating noise as a mere annoyance or as something that "Karens" bitch about because of their priviledge.
It's polution, a health issue, something that ruins quality of life, and for people with certain health issues can be a chronic problem. It prevents people from sleeping, focusing, lowers productivity, make people "dumber", you name it.
In a lot of ways, the impact of noise can be similar to that of lead pipes. And we act like we can just tell people to deal with it, and that white noise machines and earplugs (hello ear infections!) are a solution (spoiler. I use both and it barely makes a dent in the noise sometimes).
We have to stop treating noise as a mere annoyance or as something that "Karens" bitch about because of their priviledge.
It's polution, a health issue, something that ruins quality of life, and for people with certain health issues can be a chronic problem. It prevents people from sleeping, focusing, lowers productivity, make people "dumber", you name it.
In a lot of ways, the impact of noise can be similar to that of lead pipes. And we act like we can just tell people to deal with it, and that white noise machines and earplugs (hello ear infections!) are a solution (spoiler. I use both and it barely makes a dent in the noise sometimes).
How is that an issue for you and not an issue for drivers who obviously can’t hear other cars?
Cyclists who ride regularly in traffic subconsciously use sound and to a lesser extent air pressure to detect and map the movements of larger vehicles. Unlike eyesight requires a head movement to detect anything not in a field of view in front of the cyclist, sound and air pressure changes can be detected from all directions. The noise of a car approaching from the rear gives an early indication that you are about to be overtaken, which reduces the potential to be surprised/frightened. Similarly the air pressure change can give an indication of the size of the vehicle - getting overtaken by a prime mover is different to a hatchback.
Increasingly, modern car drivers are enclosed in noise dampened, environmentally controlled environments with some sort of sound entertainment playing (music, podcast, talkback radio). So car drivers are less able to make good use of sound and other cues for detecting other traffic.
The lack of sound from hybrid cars, for example the Toyota Prius when accelerating in electric mode, has caught me by surprise while cycling. Not knowing you are about to be overtaken can be dangerous because there is an instinctive fight/flight response which can cause a sudden flinch or overreaction away from the surprise and you naturally turn your head to look at the perceived danger. As you are normally cycling on the edge of the roadway there is a higher potential to now accidentally ride over/into an obstruction (drainage grate, kerb, pothole) and come off your bike.
Increasingly, modern car drivers are enclosed in noise dampened, environmentally controlled environments with some sort of sound entertainment playing (music, podcast, talkback radio). So car drivers are less able to make good use of sound and other cues for detecting other traffic.
The lack of sound from hybrid cars, for example the Toyota Prius when accelerating in electric mode, has caught me by surprise while cycling. Not knowing you are about to be overtaken can be dangerous because there is an instinctive fight/flight response which can cause a sudden flinch or overreaction away from the surprise and you naturally turn your head to look at the perceived danger. As you are normally cycling on the edge of the roadway there is a higher potential to now accidentally ride over/into an obstruction (drainage grate, kerb, pothole) and come off your bike.
Are you Batman?
Yeah people will need to get aware of that. I'm European and drive a Renault Zoe. It plays some sort of "whoooooo" noise from under the bonnet/hood when you drive slower than 30 km (19 mi).
On one hand, I think it's dumb because why am I explicitly making noise? So I turned it off. But then I scared the living hell out of two shopping ladies when I unintentionally crept up behind them, and now I always leave it on.
On one hand, I think it's dumb because why am I explicitly making noise? So I turned it off. But then I scared the living hell out of two shopping ladies when I unintentionally crept up behind them, and now I always leave it on.
Not much benefit from any kind of engine and noise when people walk or cycle with earphones. That is very usual view for me nowadays. Worse if they also stare at they phones too - blind and deaf at will.
I've said this before in comments but I just really have trouble understanding people who can walk--especially in cities--with earphones. I know some are less isolating than others--some like the pass through mode on the Airpod Pros. But I don't even really like earphones on a forest path much less a city street.
I guess it's somewhat a matter of what you're used to. I grew up pre-Walkman and have just never gotten into the habit of wearing earphones like that.
I guess it's somewhat a matter of what you're used to. I grew up pre-Walkman and have just never gotten into the habit of wearing earphones like that.
That or we can get to a point where we reduce cars in cities to a minimum. We'll probably still need car noise for the few that exist but the better solution in most ways is just to have way less cars.
i have a crazy dream that all roads would be underground... how beautiful the landscape would be without roads...
You'd need a lot of exit ramps going up though, and it would be pretty tricky for emergency services to reach the places they need to go to. Personally I'm a big fan of reducing through traffic as much as possible and banning vehicles other than for the disabled and emergency services from city cores.
yea, i think logistically its super hard and most likely not practical at all, but it would be amazing if possible...
Have you read Eliezer Yudkowsky's April Fools' Day confession? https://yudkowsky.tumblr.com/post/81447230971/my-april-fools...
i havent, thanks for the link ^^
> We could have big houses, with windows that shutter in the summer mornings to keep out every bit of the too-early light of dawn, or shutter in the night to leave the stars absolutely untouched. We could have roofs that let in the sun.
oh god, yes please!
> We could have big houses, with windows that shutter in the summer mornings to keep out every bit of the too-early light of dawn, or shutter in the night to leave the stars absolutely untouched. We could have roofs that let in the sun.
oh god, yes please!
Depends on the street. Once you get above a certain speed most of the noise is tire noise, not engine noise.
https://en.wikipedia.org/wiki/Roadway_noise
https://en.wikipedia.org/wiki/Roadway_noise
In my experience (living a mile away from a motorway), most of the noise is caused by the wheel bearings of badly maintained lorries instead of tires. One can usually tell by the high pitched noise.
I'm surprised that noise propagates far enough for you to hear. In my experience, the noise that propagates furthest from roads is the low frequency tire rumble.
Unless you live in a city, in which case most of the noise is emergency vehicles ;)
I'm extremely skeptical this is something that can be addressed by noise cancellation, either.
I'm extremely skeptical this is something that can be addressed by noise cancellation, either.
There have been discussions about adding back artificial noise, since a noiseless car would be extremely difficult to detect for people who don't have sight.
Also a fair amount of noise generated by cars is not the engine; for example, you have the sound of the tires rolling on the pavement.
Also a fair amount of noise generated by cars is not the engine; for example, you have the sound of the tires rolling on the pavement.
Most of the time on certain environments you don’t hear the cars motors at all, all you hear are the tires having a contact with the ground.
Edit: removing my comment because I was wrong. Turns out tire noise can be louder. Thanks to commenters below for correction!
Combustion engine is only louder below about 35 mph.
https://en.wikipedia.org/wiki/Roadway_noise
"...rolling tires driving on pavement is found to be the biggest contributor of highway noise which increases with higher vehicle speeds."
https://en.wikipedia.org/wiki/Roadway_noise
"...rolling tires driving on pavement is found to be the biggest contributor of highway noise which increases with higher vehicle speeds."
In the US there are plenty of poorly maintained vehicles on the road emitting a lot of other nosies - squeaky belts, damaged or missing mufflers, rattling panels, worn brake rotors or pads.
Most states have very lax inspection requirements.
Even in my state, which supposedly is one of the strictest on inspections, it's surprisingly easy to have a dangerous failing car pass.
Living near a busy intersection you hear all sorts of weird mechanical failures as cars brake and accelerate from the stoplight.
Most states have very lax inspection requirements.
Even in my state, which supposedly is one of the strictest on inspections, it's surprisingly easy to have a dangerous failing car pass.
Living near a busy intersection you hear all sorts of weird mechanical failures as cars brake and accelerate from the stoplight.
While a highway with high speed traffic sounds like a loud whooshing sound, from tires on pavement and air displacement. Engine sounds are almost impossible to notice.
Intersection sounds like <35 mph, so you are agreeing with me.
Intersection sounds like <35 mph, so you are agreeing with me.
Afraid not. Most noise from modern cars is tyre noise at speeds where you're most likely to encounter it.
I have a weird obsession with road noise and how it relates to road surface construction.
I have a weird obsession with road noise and how it relates to road surface construction.
Isn’t it also the case that a big heavy car with gigantic tires is louder than a lighter car with narrower tires? A Tesla Model X is pretty dang loud at 45 MPH, compared to something like a BMW i3 that weighs half as much and looks like it wears bicycle tires.
Absolutely. Basically the volume of sound emitted increases in proportion to the tyre size and speed, and also is affected by its tread pattern.
In short, the road noise from tyres is due to air being compressed by the tread and then released again. It's basically a constant rolling version of clapping your hands.
Modern formulations of tarmac are designed to settle with air channels (called voidage) to provide an exhaust for that air, significantly reducing the volume. If you want more information on a couple of types, look up stone-matrix asphalt or open-graded friction course. Concrete on the other hand is notoriously poor for sound reduction, because the surface is so much smoother.
As a rough rule of thumb, quietened surfaces come in at 6-9db lower than a comparable non-quietened surface.
ARFC is another kind, made of recycled rubber mixed as a secondary aggregate. It's commonly used as a quiet and long lasting surface in parts of the US, and has the advantage of being a good product for using up waste tyres. In the UK we have different compounds, which do similar things. The M4 between Swindon and Bristol is a particular treat to drive on acoustically.
Undersurface is potentially an issue too. For example, concrete surfaced in mono-aggregate based tarmac has a tendency to resonate and "sing". Concrete with undulations does the same, though for different reasons.
I could go on for some time but it's kinda dull.
In short, the road noise from tyres is due to air being compressed by the tread and then released again. It's basically a constant rolling version of clapping your hands.
Modern formulations of tarmac are designed to settle with air channels (called voidage) to provide an exhaust for that air, significantly reducing the volume. If you want more information on a couple of types, look up stone-matrix asphalt or open-graded friction course. Concrete on the other hand is notoriously poor for sound reduction, because the surface is so much smoother.
As a rough rule of thumb, quietened surfaces come in at 6-9db lower than a comparable non-quietened surface.
ARFC is another kind, made of recycled rubber mixed as a secondary aggregate. It's commonly used as a quiet and long lasting surface in parts of the US, and has the advantage of being a good product for using up waste tyres. In the UK we have different compounds, which do similar things. The M4 between Swindon and Bristol is a particular treat to drive on acoustically.
Undersurface is potentially an issue too. For example, concrete surfaced in mono-aggregate based tarmac has a tendency to resonate and "sing". Concrete with undulations does the same, though for different reasons.
I could go on for some time but it's kinda dull.
> I could go on for some time but it's kinda dull.
I find civil engineering is often quite interesting, because the tradeoffs and issues can be surprisingly inobvious.
I find civil engineering is often quite interesting, because the tradeoffs and issues can be surprisingly inobvious.
Do you have a blog? (I checked your bio, but your personal domain seems to redirect to your work now.)
Not ATM. I've been thinking of writing a book on acoustics and perception of sound though for about 5 years, which is related to how I know about this sort of stuff. I've also built speakers in my spare time.
I've always been fascinated by sound and how people perceive it. I'm also a classical pianist and guitarist, amongst other things, which may explain it, or be caused by it. Who knows?
It's not something I thought other people would care to read about though, hence never doing it. Maybe time to re-evaluate that.
I've always been fascinated by sound and how people perceive it. I'm also a classical pianist and guitarist, amongst other things, which may explain it, or be caused by it. Who knows?
It's not something I thought other people would care to read about though, hence never doing it. Maybe time to re-evaluate that.
Small naturally aspirated gasoline engines are also quieter than turbodiesels. With some good noise dampening in the engine compartment and exhaust system some cars are surprisingly quiet even at low speeds. Also, some roads are louder than others (cobblestone being very loud regardless of speed).
Noise is a complicated thing. If you're in a neighborhood that's got low-speed traffic and the occasional car engine is what's disrupting your peace, more penetration of EVs will be great. But EVs are also heavy, and cars are getting heavier in general. That isn't going to do you any favors on tire noise. I wouldn't expect the noise coming off of a freeway to change much.
Here in Germany they have deployed so-called "whisper/porous asphalt" on the highways leading into some major city centres. Since it's more porous than regular asphalt it absorbs noise (and rain) much better, but the drawback is that it's more expensive to manufacture and is less durable.
Just saying that there are probably lots of different noise reduction techniques that all add up their percentages, but these will only be put in place if noise pollution is taken as serious as it needs to be.
Just saying that there are probably lots of different noise reduction techniques that all add up their percentages, but these will only be put in place if noise pollution is taken as serious as it needs to be.
My (US) state DOT paved over the concrete highways with rubberized asphalt for similar reasons. The asphalt doesn’t last as long, but it’s quieter and cheaper than concrete repairs. It’s also something that uses up old tires.
I live next to a busy street with electric trolleybuses (essentially rubber wheeled city buses that use electrical power from overhead lines.) They're very quiet compared to the odd diesel-powered truck, but the tires on pavement still produce a noticeable amount of noise.
Up from certain speed more noise is coming from wheels, not engine. Especially if there are defects in the pavement.
Reducing the noise floor is likely to make it more disruptive to have the window open, because the intermittent outliers (trains, buses, motorcycles, trucks) will be even more prominent.
I live outside Muni/Caltrain. They're not great, noise-wise, but the motorcycles are 10000x worse. I get a number going by a day, and I just can't understand why they're allowed to be so absurdly loud.
Buses/trains are relatively quiet, outside of a few edge cases like tracks scraping or honking when someone's in their way - rare occurrences.
Buses/trains are relatively quiet, outside of a few edge cases like tracks scraping or honking when someone's in their way - rare occurrences.
My intuition about this is that the deflection, intensity, and directionality of the noise from motorcycles impacts street level noise more than trains in a rail corridor. I believe that is why good street planning incorporates natural features that absorb and deflect noise, like greenery on street corners, for example.
The Caltrain (and other trains but Caltrain is more frequent) going by San Mateo is brutal. Their horn is almost constantly on due to the many ground level intersections and they are ear drum busting loud (by regulation no less).
Yeah, I do imagine it depends a lot on where you are. Even a few blocks from here the Caltrain can get much louder.
That seems excessive (from a YouTube video).
In Britain, within towns there's usually gates on either side of the road, so it's not necessary for the train to use its horn.
https://youtu.be/uaWG04vKYLg
In Britain, within towns there's usually gates on either side of the road, so it's not necessary for the train to use its horn.
https://youtu.be/uaWG04vKYLg
Areas where every level crossing is this good can be designated as quiet zones, but few municipalities want to spend the money on that. Train tracks are usually in industrial/commercial areas; homes near them are, shall we say, not centers of political power.
I don’t know. I wouldn’t call downtown San Mateo and Burlingame either industrial zones or far away from political influence.
There are gates in San Mateo but they still blast their horns. I believe minimum of 96 decibels at 100 feet is required.
My dorm was a bus stop. Each time the bus came there were air brakes, a recording announcing the route and station, and the warning beeps for kneeling and wheelchair ramp extension. Fortunately it did not have a shelter, as many bus shelters in Chicago now beep continuously so that blind people can find them.
My first apartment was outside a level crossing frequented by Amtrak and Union Pacific. The federally required horn blasts - 2 long, 1 short, 1 long - overwhelm anything you might be doing or thinking about, resonate in your chest cavity. The building shakes, and the air becomes thick with diesel fumes and sediment kicked up from the railroad bed.
After an hour, I forget that the freeway is even there.
My first apartment was outside a level crossing frequented by Amtrak and Union Pacific. The federally required horn blasts - 2 long, 1 short, 1 long - overwhelm anything you might be doing or thinking about, resonate in your chest cavity. The building shakes, and the air becomes thick with diesel fumes and sediment kicked up from the railroad bed.
After an hour, I forget that the freeway is even there.
I'm on an intersection with caltrain, muni, and a freeway, but of course it can only be so informative. I'm not trying to say "Buses and trains aren't a problem" at all, I'm saying fuck motorcycles.
Personally, I would favor "noise tax" for any noise generated, regardless of the reason. (I may be biased, I am noise-sensitive.)
In this case, it will put pressure to avoid, or reduce, noise when possible (as it directly lowers costs). It's not only cars - all neighbors with a passion for loud music (or quarrels), repair works taking longer and louder than necessary.
In this case, it will put pressure to avoid, or reduce, noise when possible (as it directly lowers costs). It's not only cars - all neighbors with a passion for loud music (or quarrels), repair works taking longer and louder than necessary.
I absolutely detest Harley's and other loud motorcycles and don't understand why there are no restrictions on vehicular noise. Why do certain individuals get to impose their absurdly loud vrooms on everyone else just because they want to? It's such a trivially stupid negative externality that has no reason to exist.
There are. They can and should be ticketed if they remove their mufflers or put in exhausts above the legal limit but lots of them DGAF
This is the whole point of riding around on a vibrating sex toy -- to be obnoxious to everyone else, to shout 'look at me'.
Harley Davidson was held sued by the EPA for selling aftermarket "offroad-only" parts for customers' daily drivers. https://article.images.consumerreports.org/prod/content/dam/...
If someone had to pay $1 to use their car horn I think we’d have much better drivers as well
Most Romanian drivers would be bankrupt within a day or so.
There's always going to be a lot of noise in dense areas. It doesn't even have to be a city. Any buildings with shared walls too.
I used to live along Lawrence expressway in the Bay Area. At 45-50 mph, the noise that drown everything out was the tire noise. The Teslas were just as bad as any other modern ICE car.
Where the engine noise was noticeable was low speed intersections when cars would accelerate and the tire noise would be negligible.
Where the engine noise was noticeable was low speed intersections when cars would accelerate and the tire noise would be negligible.
It would actually be fine with current gasoline cars minus motorcycles and small handful of people who purposefully make their vehicles loud for... who knows what purpose.
Motorcycles as stock under EURO5 typically aren't that loud, it's the obnoxious after-market exhausts that make them so loud particularly with the baffles removed.
I find it obnoxious and I am a motorcyclist.
I find it obnoxious and I am a motorcyclist.
> but I’m hopeful that we’ll someday get to a point where (almost) all of the vehicles on our roads will be electric.
While we wait for that why can't architects/planners take soundproofing more seriously (if they've considered it at all) and actually make the walls and windows inside a building soundproof. It's not even outside noise, I lived in apartments where I could hear my adjacent neighbors.
While we wait for that why can't architects/planners take soundproofing more seriously (if they've considered it at all) and actually make the walls and windows inside a building soundproof. It's not even outside noise, I lived in apartments where I could hear my adjacent neighbors.
The EPA has noise abatement regulations. Your city and state may also be involved. A lot of things are exempted usually though, such as trains, planes and automobiles.
After about 20mph, tire noise will overwhelm the noise made by even a (modern) ICE. Don’t get your hopes up. Granted, electric takes away the thing you attach a jackassly loud exhaust to, but tires are noisy.
When it comes to passenger cars, most noise is generated by tires hitting the road. Especially at higher speeds the engine noise doesn’t really contribute anything meaningful to the noise you hear. So electric cars won’t solve this problem.
When I was living in Singapore, all the rich people were on the higher floors where you don't hear the road anyway. Or they had their own villa with garden. Back then, noise pollution was considered mostly a poor people issue. Glad to see that they are now finally getting an upgrade, too :)
no paywall: http://archive.is/zo83N
This will be revolutionary if it is deployable at scale. One thing I have learnt over the years is to avoid apartments which have any windows towards the road.
[deleted]
With certain windows, for certain sounds, you can put actuators on the window itself. They vibrate the glass as a speaker. Unfortunately it is very tricky- the resonant frequency of glass panes is far lower than sound, so its very hard to make the glass all move together. Instead it prefers to take on wavy bends, which can even create their own noise.
One neat idea is electrostatic speakers! They're one of the more exotic speaker types, but have unparalleled quality at low volumes. However they are prone to distortion as volume increases and require high (100+) voltage supplies. They can be dangerous and fragile.
The idea is you stretch a mylar film very tightly into a rectangle, and then sandwich it between two metal meshes, with an air gap. By putting voltage on the meshes, static electricity pulls the mylar forward and back while keeping it almost perfectly flat.
You can put meshes (or ITO films) inside a double pane window to create a very even force over the whole window, making it an excellent transducer. It requires far higher voltages to move glass, though. Putting mylar in between the panes doesnt work (you need some free space to create proper cancellation- oversimplifying) and putting mylar on the outside is dangerous. Tricky problem.
One neat idea is electrostatic speakers! They're one of the more exotic speaker types, but have unparalleled quality at low volumes. However they are prone to distortion as volume increases and require high (100+) voltage supplies. They can be dangerous and fragile.
The idea is you stretch a mylar film very tightly into a rectangle, and then sandwich it between two metal meshes, with an air gap. By putting voltage on the meshes, static electricity pulls the mylar forward and back while keeping it almost perfectly flat.
You can put meshes (or ITO films) inside a double pane window to create a very even force over the whole window, making it an excellent transducer. It requires far higher voltages to move glass, though. Putting mylar in between the panes doesnt work (you need some free space to create proper cancellation- oversimplifying) and putting mylar on the outside is dangerous. Tricky problem.
You mentioned danger twice. Can expand on this aspect of the tech?
By the nature of the device the meshes need to be fairly exposed. They can be enameled so as not to shock you, but only barely. Any scratch, rubbing, or other wear can expose bare metal at >1 kV. That is a major fire risk; any spark is presumed deadly in electrical engineering. Dust accumulates everywhere, and you'd be amazed how much people mistreat electronics. Leaves, dirty laundry and dust may as well be tinder.
The even bigger concern is mostly that a moderately loud speaker system (>50-150 watts) can electrocute you. I mean that literally, as the portmanteau of electricity and execution. 1 kV is easily enough to put electricity through your heart; 50 milliamps would be lethal. 50 mA at 1 kV is only 50 watts, less than a laptop charger. A big set of electrostatic speakers can just stop your heart if you're very unlucky.
The even bigger concern is mostly that a moderately loud speaker system (>50-150 watts) can electrocute you. I mean that literally, as the portmanteau of electricity and execution. 1 kV is easily enough to put electricity through your heart; 50 milliamps would be lethal. 50 mA at 1 kV is only 50 watts, less than a laptop charger. A big set of electrostatic speakers can just stop your heart if you're very unlucky.
This invention seems like something straight out of a Sharper Image catalog. Neat concept, but needs a few generations of miniaturization before I'd remotely consider it.
If you're going to put up a wall up on your websites, make sure they load right away instead of loading the whole article before the paywall gets loaded.
I was able to read this entire article despite its pay wall by screenshotting the article before the pay wall came up. I had to reload the page, screenshot several times, and time it right but I was able to read the whole article.
I was able to read this entire article despite its pay wall by screenshotting the article before the pay wall came up. I had to reload the page, screenshot several times, and time it right but I was able to read the whole article.
You can also read it by viewing the source or by deactivating the paywall
Just press Esc to stop loading the webpage before the wall shows up. Needs practice to time it correctly, but it works well. Other option is to just disable JS.
I'm actually, right now, spending about 6k trying to sound proof my work area. If I ware a billionaire, I'd give these people millions of dollars as investment. Or to another team that could figure it out how to turn your hearing on/off on command.
Maybe in the long run we could decentralize our habitat and eliminate the lions share of the problem
tell me about it, I'm working and saving some money so the future me can get a cabin in the woods somewhere. or on the ice, if I'm doing really well.
What's a "cabin on the ice"?
Fish house basically.
yeah, this was probably on my copy/paste from a previous conversation. sorry, this is not a cabin on the ice
Hopefully remote working will become much more normal and help with that.
This guy says you can build high-performance acoustic panels with old towels.
https://youtu.be/pABvTWSxOes
https://youtu.be/pABvTWSxOes
yeah, I follow him on youtube. But, what I think he suggest on this video is a solution to the reverb problem that he faces recording his videos.
I want to stop noise from coming in to my entire room, both acoustic and structural.
I want to stop noise from coming in to my entire room, both acoustic and structural.
> This guy says you can build high-performance acoustic panels with old towels.
Towels, acoustic panels and other materials are good at reducing echos but it doesn't really do much at all for reducing the amount of sound that can enter or escape a room.
If you had an open room with a hardwood floor, you'd likely get a lot of echos when talking normally. That's where things like acoustic panels help out.
If you want to dampen the noise of your neighbor's kids screaming like maniacs you'd have to do a pretty serious amount of sound proofing with other strategies. It's a lot more complicated.
Towels, acoustic panels and other materials are good at reducing echos but it doesn't really do much at all for reducing the amount of sound that can enter or escape a room.
If you had an open room with a hardwood floor, you'd likely get a lot of echos when talking normally. That's where things like acoustic panels help out.
If you want to dampen the noise of your neighbor's kids screaming like maniacs you'd have to do a pretty serious amount of sound proofing with other strategies. It's a lot more complicated.
Sound treatment uses acoustic panels to make a room with a flat frequency response and minimal reverb. They damp the room's natural resonant peaks and reflections.
Sound isolation keeps sound from getting into and out of the room. It's a separate problem, and you can only solve it with mass and physical separation - e.g. building a room inside a room with massive walls and rubber isolation for the floor.
If you do it properly you have to pay a consultant to design a solution for you, because it's so easy to get it wrong.
Sound isolation keeps sound from getting into and out of the room. It's a separate problem, and you can only solve it with mass and physical separation - e.g. building a room inside a room with massive walls and rubber isolation for the floor.
If you do it properly you have to pay a consultant to design a solution for you, because it's so easy to get it wrong.
Before you drop all that money try this: run low volume ambient noise such as rain or distant thunder. That serves as a masking sound and will have a strong effect on getting rid of other non-periodical sounds. Your brain just tunes it out after a while and it tunes quite a bit of the background noise out with it.
yes, that's what I've been doing until this week. but since I'm looked inside the house since Feb this year I'm not spending money on anything. so I decided to give myself this cool room.
I'll do a 360 picture of it after it's done. like I did with the victorribeiro.com/3Dsphere but with picture instead of a render
I'll do a 360 picture of it after it's done. like I did with the victorribeiro.com/3Dsphere but with picture instead of a render
That looks gorgeous. What did you use to make the rendering?
Please let me know when you have it all built I'm very curious to see what it will look like in real life. And don't forget to take 'before' and 'after' readings with a sound level meter!
Please let me know when you have it all built I'm very curious to see what it will look like in real life. And don't forget to take 'before' and 'after' readings with a sound level meter!
I don't know if you're doing ceilings or floors as well, but a cork underlay can go under your current flooring and works WONDERS for footsteps, running and other transition sounds between floors. We did ours through Home Depot- you can order it in the carpet section. You can hire them to install or do it yourself. Went from hearing a herd of buffalo walking to glorious silence.
I did all the walls and ceiling. Dry wall + glass wool, on top of bricks.
How do you soundproof a room without tearing out the walls and replacing them with thicker ones?
Can't you install panels on top of the walls?
No, not really. Soundproofing means preventing sound from entering or exiting a volume. Because of the way sound works, a quite small leak will result in quite a lot of sound entering or exiting a volume.
20 dB is a ~4x increase in perceived sound volume, but a 10x increase in the actual pressure of the sound wave. So, oversimplifying, if you block off 90% of the sound waves entering a volume, the remaining pressure spreads out to 10x weaker waves... which are still 25% as loud. Keep in mind that this is covering 90% of the floor, walls, ceiling, doors and windows in perfectly sound-blocking material, which does not exist.
To reduce volume levels by 90%, you need to perfectly isolate 97% of the sound leaking in. You literally need to build a new room inside the old one. That's before you even account for the fact that your ears will adjust and sounds need to be much quieter to keep from picking up on them.
Preventing sound from exiting a volume is even worse. Sound has quite low absorption coefficients even in things like open cell foam; anechoic chambers rely heavily on shapes that trap sound and cause it to echo through foam dozens of times so that it's sufficiently attenuated before it bounces back out. Most reasonably airtight rooms are painfully loud because sounds you normally consider quiet (eg footsteps) are not attenuated as normal.
Keep in mind that even if you think a room is reasonably airtight -eg when you have an open window, your door closes far more easily than when the window is closed- it's really not at all. You've probably got vents etc that allow lots of air to move in and out of the room.
In a well-sealed room, sound will echo ~100 times (a second or two) before attenuation makes it much quieter. That pressure is just bottled up and it will escape through even tiny cracks, and if you were to listen at one of those cracks you'd hear much more clearly than if the room wasn't soundproofed at all. In that case, the soundproofing is just acting like a funnel or a crack in a pressure vessel. Unless you've got comprehensive soundproofing and a way to increase attenuation, all you're doing is causing the sound to escape from smaller spots.
When you see people recording and they have just a few acoustic panels up, the point is not to make the room any quieter. In fact they usually want the opposite- you want sound to exit the room as easily as possible, to prevent echoes. If you hang up too many panels, you prevent that from happening and you don't really decrease the volume of sound from the outside.
Acoustic panels are best used sparingly to dissipate or break up echoes from a very specific place, like directly in front of the recording, or behind electronics/noise sources.
20 dB is a ~4x increase in perceived sound volume, but a 10x increase in the actual pressure of the sound wave. So, oversimplifying, if you block off 90% of the sound waves entering a volume, the remaining pressure spreads out to 10x weaker waves... which are still 25% as loud. Keep in mind that this is covering 90% of the floor, walls, ceiling, doors and windows in perfectly sound-blocking material, which does not exist.
To reduce volume levels by 90%, you need to perfectly isolate 97% of the sound leaking in. You literally need to build a new room inside the old one. That's before you even account for the fact that your ears will adjust and sounds need to be much quieter to keep from picking up on them.
Preventing sound from exiting a volume is even worse. Sound has quite low absorption coefficients even in things like open cell foam; anechoic chambers rely heavily on shapes that trap sound and cause it to echo through foam dozens of times so that it's sufficiently attenuated before it bounces back out. Most reasonably airtight rooms are painfully loud because sounds you normally consider quiet (eg footsteps) are not attenuated as normal.
Keep in mind that even if you think a room is reasonably airtight -eg when you have an open window, your door closes far more easily than when the window is closed- it's really not at all. You've probably got vents etc that allow lots of air to move in and out of the room.
In a well-sealed room, sound will echo ~100 times (a second or two) before attenuation makes it much quieter. That pressure is just bottled up and it will escape through even tiny cracks, and if you were to listen at one of those cracks you'd hear much more clearly than if the room wasn't soundproofed at all. In that case, the soundproofing is just acting like a funnel or a crack in a pressure vessel. Unless you've got comprehensive soundproofing and a way to increase attenuation, all you're doing is causing the sound to escape from smaller spots.
When you see people recording and they have just a few acoustic panels up, the point is not to make the room any quieter. In fact they usually want the opposite- you want sound to exit the room as easily as possible, to prevent echoes. If you hang up too many panels, you prevent that from happening and you don't really decrease the volume of sound from the outside.
Acoustic panels are best used sparingly to dissipate or break up echoes from a very specific place, like directly in front of the recording, or behind electronics/noise sources.
that was a very good explanation. I'm awaiting for my remodeling to be done so I can see if I spent all that money for nothing. Got a new wooden door and new windows. If everything works, I'll share my project here on HN.
Unless you need to record sound, noise cancelling headphones are much more cost effective. If you do need to record sound, directional microphones and noise shields for them are a little more practical.
I'm always dumbfounded when I see that noise emissions are still not taken seriously and not enforced.
I live near a freeway and the cars don't bother me that much (I'm far away that they sound like white noise). But the motorbikes, however, are the works.
Some of them don't make that much noise, but the outliers make you go crazy. It's a shame really
I live near a freeway and the cars don't bother me that much (I'm far away that they sound like white noise). But the motorbikes, however, are the works.
Some of them don't make that much noise, but the outliers make you go crazy. It's a shame really
I was born in the country (UK) we could hear individual cars coming from a mile away. We live about a mile from a 2-lane motorway: it's been bliss for me in the depth of lockdown that at times it's been silent, and again I've been able to hear (quietly) individual vehicles at night, or none at all.
My kids, brought up with it, were surprised to even be told there is motorway noise, they simply don't notice it.
My kids, brought up with it, were surprised to even be told there is motorway noise, they simply don't notice it.
Yeah, you actually need to be pretty far from roads with any traffic not to hear anything at all.
I'm maybe 500 feet from a 2-lane road and about a mile from an Interstate in a fairly spread out area. It's not exactly noisy but with windows open and no music or anything playing, you definitely hear the road traffic.
I'm maybe 500 feet from a 2-lane road and about a mile from an Interstate in a fairly spread out area. It's not exactly noisy but with windows open and no music or anything playing, you definitely hear the road traffic.
> but the outliers make you go crazy
Agreed, so very much. I live across the way from an old-age care home and, based on stereotypes, you'd figure that would be quiet living. Not so much. Their landscaping crew gets out with leaf blowers every day, they have a weekly generator run-up test that lasts for half an hour and pulses with a deep bass, and every few hours on every nice day they pump out the best hits from the 1940s and 1950s on their outdoor patio.
Almost all of these are louder than the city's rules permit but code enforcement has told me that because both buildings face each other over a privately-owned parcel (one of these "privately owned public spaces"), the noise transmission rules do not apply.
I found this out after I called the care home, twice, to ask if they could maybe turn down the music or do the generator test later in the day (when more people are out and it would be drowned out by other ambient noise) only to be told, politely, to bugger off.
I like living in a city and am not going to move--it's not that annoying, compared to benefits I get in return--but sometimes I wish the commons weren't so tragedy.
Agreed, so very much. I live across the way from an old-age care home and, based on stereotypes, you'd figure that would be quiet living. Not so much. Their landscaping crew gets out with leaf blowers every day, they have a weekly generator run-up test that lasts for half an hour and pulses with a deep bass, and every few hours on every nice day they pump out the best hits from the 1940s and 1950s on their outdoor patio.
Almost all of these are louder than the city's rules permit but code enforcement has told me that because both buildings face each other over a privately-owned parcel (one of these "privately owned public spaces"), the noise transmission rules do not apply.
I found this out after I called the care home, twice, to ask if they could maybe turn down the music or do the generator test later in the day (when more people are out and it would be drowned out by other ambient noise) only to be told, politely, to bugger off.
I like living in a city and am not going to move--it's not that annoying, compared to benefits I get in return--but sometimes I wish the commons weren't so tragedy.
This is something that drives me banana. The answer you'll get is always "Well, cities are noisy, deal with it or live in the suburb.
But the thing is they don't have to be. Sure, you have to expect people talking, cars going through, people mowing the grass, the occasional honking. But even in the middle of Manhattan, the only noise that will wake you up in the morning are people being assholes or breaking rules. Special construction permits that have no business being issued (eg: jackhammers in the middle of the night), people screaming (why?), harleys motorcycles (why is that legal?), neighbors blasting music (you can hear it just fine, can you lower it a bit?), musicians in apartments (can't you use an electronic drum to practice?).
Everything's avoidable. People are just inconsiderate, and/or the problem isn't taken seriously. But no, it's not inherent to living in a dense area, unless you're talking about "being surrounded by assholes" being inherent to cities. Then yeah.
suburbs aren't really a solution because people can be assholes everywhere. But even if they weren't, current pushes to get rid of restrictive zoning means you won't be safe in a suburb for much longer anyway. We need solutions for noise in densely populated areas because we're not going to be able to avoid it long terms. The solutions all exist, they just need to be implemented and enforced.
But the thing is they don't have to be. Sure, you have to expect people talking, cars going through, people mowing the grass, the occasional honking. But even in the middle of Manhattan, the only noise that will wake you up in the morning are people being assholes or breaking rules. Special construction permits that have no business being issued (eg: jackhammers in the middle of the night), people screaming (why?), harleys motorcycles (why is that legal?), neighbors blasting music (you can hear it just fine, can you lower it a bit?), musicians in apartments (can't you use an electronic drum to practice?).
Everything's avoidable. People are just inconsiderate, and/or the problem isn't taken seriously. But no, it's not inherent to living in a dense area, unless you're talking about "being surrounded by assholes" being inherent to cities. Then yeah.
suburbs aren't really a solution because people can be assholes everywhere. But even if they weren't, current pushes to get rid of restrictive zoning means you won't be safe in a suburb for much longer anyway. We need solutions for noise in densely populated areas because we're not going to be able to avoid it long terms. The solutions all exist, they just need to be implemented and enforced.
> But the motorbikes, however, are the works.
And they do it deliberately. The concept of "loud pipes save lives" is so annoying. Maybe on the highway, but the way they rev their engines in neighborhoods is not necessary or even in town.
And they do it deliberately. The concept of "loud pipes save lives" is so annoying. Maybe on the highway, but the way they rev their engines in neighborhoods is not necessary or even in town.
A low tech alternative mentioned in the paper is the Plenum Window. Imagine sliding glass shower doors, but with a bigger gap between panes for airflow. It also claims 10dB reduction, and doesn’t need a computer :)
Also from the paper: typical noise cancellation systems create local dead zones of radius ~1/10th the wavelength of blocked sound. E.g., you can block a 1KHz wave within 3.4cm of an error correcting microphone. Good enough for noise canceling headphones but not a whole room.
This work builds on an earlier finding that you can treat the window itself as a point source. Noise cancellation at its source is much more effective, so this way they’re able to create a dead zone the size of your apartment.
Also from the paper: typical noise cancellation systems create local dead zones of radius ~1/10th the wavelength of blocked sound. E.g., you can block a 1KHz wave within 3.4cm of an error correcting microphone. Good enough for noise canceling headphones but not a whole room.
This work builds on an earlier finding that you can treat the window itself as a point source. Noise cancellation at its source is much more effective, so this way they’re able to create a dead zone the size of your apartment.
That's with one microphone and presumably a single speaker. I wonder how well one could do with several microphones around the room and several speakers, with their relative positions known accurately and some computing power to generate the best possible reverse sound distribution.
[deleted]
You’d need a lot of speakers (one every 6.8cm) to get the same coverage with an array inside the room.
And it's a much harder problem, because antiphase sound from multiple sources will interfere with itself and probably also interact with room resonances, potentially making the problem worse in some locations.
I reckon the attenuation you can get will be something like the cosine of the phase difference between the speakers. Basically you'd need to them to be much closer than a single wavelength, otherwise they'll amplify the sound, rather than attenuating it.
I reckon you could probably do some extremely local noise cancelling (which would only work for a few people at most), but then the speakers don't only need to balance out the external noise, but also each other, which could require extreme volumes if the distributions of speakers is a bad fit.
I reckon you could probably do some extremely local noise cancelling (which would only work for a few people at most), but then the speakers don't only need to balance out the external noise, but also each other, which could require extreme volumes if the distributions of speakers is a bad fit.
The book Daemon by Daniel Suarez has a similar concept in it. The evil guys put a few cameras and ultrasonic speakers in the room. They can create a localized area of intense sound to really fuck up the good guy's head without any indication of what's going on, as well as beam voices directly into his head - silence on the walkie talkies and no physical indication of what's going on. If you limit yourself to one occupant, and can get good 3d tracking of their ears, then theoretically a few speakers on a pan/tilt mount should be able to do ANC over the entire room. Of course if you have to do it for multiple occupants then you would need a speaker every 6.8 cm.
The audio device mentioned in Daemon exists. It's been tried for advertising. You can buy one if you want.[1][2] The audio quality is not very good, but voice will get through. The main application is museums, where you have one next to each exhibit, pointing down from above.
The problem with creating nulls by cancellation is that you create peaks somewhere else. You could null out one person (maybe only one ear) somewhere in the room, but multiple targets will be really hard.
[1] https://ultrasonic-audio.com/products/
[2] https://www.soundlazer.com/shop/
The problem with creating nulls by cancellation is that you create peaks somewhere else. You could null out one person (maybe only one ear) somewhere in the room, but multiple targets will be really hard.
[1] https://ultrasonic-audio.com/products/
[2] https://www.soundlazer.com/shop/
A conventional speaker creates a sphere of sound. A directional speaker like the one you linked creates a beam of sound. But an array of speakers could create a localized spot of sound by creating sound which would only add up to the target at that location. Of course there would be random fragments of parts of the sound (the unadded components) at other random places where the waves coincide, but for only one person in a room this is effectively the same as having a spot of sound with no other side effects.
I did forget to think that two ears would be like having two different people - there would be two target points where the sound would have to add up/subtract to the target.
I did forget to think that two ears would be like having two different people - there would be two target points where the sound would have to add up/subtract to the target.
That's not how directional ultrasonic speakers work. They exploit the fact that propagation in air is nonlinear. It's not just phase addition.
So we'll start to see noise cancelling modules integrated with point sources like washing machines, air conditioners, ceiling fans, blenders, etc., will compete at a level >10db lower than now.
Or buy a box of standalone cancelers and stick them where you need them. Like the dog's collar.
Faster please.
Or buy a box of standalone cancelers and stick them where you need them. Like the dog's collar.
Faster please.
> Imagine sliding glass shower doors, but with a bigger gap between panes for airflow. It also claims 10dB reduction, and doesn’t need a computer :)
Note that this is ~50% reduction in volume, roughly the difference between a loud and normal conversation. Noise cancelling headphones are more like 75%-87%, the difference between a loud conversation and a whisper.
Note that this is ~50% reduction in volume, roughly the difference between a loud and normal conversation. Noise cancelling headphones are more like 75%-87%, the difference between a loud conversation and a whisper.
Noise cancelling tech only cancels certain sounds though. Traffic noise works. Voices are not cancelled at all by mine.
Not all headphones are the same, and for higher frequency, quickly-changing sounds like voices, having some extra processing speed really helps. Better microphones and transducers also make a much larger difference than you'd think.
Acoustic cancellation is used at the room scale to remove vibrations from sensitive scientific experiments. Its not the tech that only works on certain sounds, its the implementations.
Acoustic cancellation is used at the room scale to remove vibrations from sensitive scientific experiments. Its not the tech that only works on certain sounds, its the implementations.
Creating a negative copy of the ambient noise - won't that increase the noise for everyone else? Say you live across the street from a neighbor who has this device. Street noise happens. It reaches you, and your neighbor's cancellation device, at roughly the same time. The device creates the cancellation wave, timed perfectly for the neighbor. That wave also propagates back toward you, and you hear it as an echo, with a delay corresponding to the width of the street.
Sound decays exponentially as a function of distance, so speakers close to you don't need to be loud. Also most speakers are also fairly directional, so i'd expect any extra energy to be absorbed by the room (as heat).
Edit: more importantly these are destructive waves, so if anything you’d actually reduce reflections back out into the world.
Edit: more importantly these are destructive waves, so if anything you’d actually reduce reflections back out into the world.
Not exactly exponentially.
Yes, it's not exponential. The sound level is inversely proportional to the square of the distance.
This is 1/d^2. Exponential would be 1/2^d.
It is actually between the two because sound is a material wave and air has friction.
depends how far away you are.
https://upload.wikimedia.org/wikipedia/commons/thumb/6/64/Ex...
https://upload.wikimedia.org/wikipedia/commons/thumb/6/64/Ex...
In high school like twenty years ago, we actually did a simple experiment demonstrating sound cancellation like this with simply speakers facing each other with polarity reversed. That surprisingly works well enough to definitely notice it working, when you are positioned in the right place, which is pretty cool.
It also works well enough to see it doesn't really do what you are describing. The energy from negative copy sound waves is being used to cancel out the original sound waves, the better it's working the less energy there is going to sound waves "escaping" to be heard anywhere else.
It also works well enough to see it doesn't really do what you are describing. The energy from negative copy sound waves is being used to cancel out the original sound waves, the better it's working the less energy there is going to sound waves "escaping" to be heard anywhere else.
If the two speakers were any closer to each other than say 80 feet or 25m (which is roughly how far sound travels in 0.1 second), I wouldn't expect you to have heard the effect I'm describing. There would have to be enough distance between the "source" and the "canceller" to throw off the timing.
[deleted]
Only as much as having a window that reflects sound waves almost-perfectly, like... a really thick pane of glass.
For what it's worth, since humans perceive sound logarithmically, a doubling sound of intensity feels like a constant (+3dB) increase of noisiness. This window would not even double sound intensity unless you're right next to it.
For what it's worth, since humans perceive sound logarithmically, a doubling sound of intensity feels like a constant (+3dB) increase of noisiness. This window would not even double sound intensity unless you're right next to it.
This and one of its sibling comments make a good point - maybe this would partially cancel the sound being reflected by the solid part of the wall. We can entertain the possibility, because we know sound in air generally reflects from a wall in the same phase in which it arrived. (If it was reversing itself we'd be in trouble again.)
No, just like noise cancelling headphones do not create any noise for people not wearing them.
If the speakers (or their combined phased-array effect) are directional, you can project antinoise with different effects in each direction.
So for the person inside the apartment it sounds like a wall in the way, attenuating sound from outside, but for the neighbour across the street, it sounds like a hole absorbing the sound instead of reflecting it like a wall.
With enough points in a directional array it starts to resemble an acoustic hologram, with some remarkable one-way properties.
If you wanted to go really far with this, you could cover the exterior walls of buildings with dense arrays, and it would dampen street sounds for everyone in the neighbourhood, indoors and outdoors. In the street it would sound a bit like there were no buildings either side to reflect sounds back into the street, yet at the same time the buildings would still block sound from neighbouring streets.
Perhaps in future cities will do this.
So for the person inside the apartment it sounds like a wall in the way, attenuating sound from outside, but for the neighbour across the street, it sounds like a hole absorbing the sound instead of reflecting it like a wall.
With enough points in a directional array it starts to resemble an acoustic hologram, with some remarkable one-way properties.
If you wanted to go really far with this, you could cover the exterior walls of buildings with dense arrays, and it would dampen street sounds for everyone in the neighbourhood, indoors and outdoors. In the street it would sound a bit like there were no buildings either side to reflect sounds back into the street, yet at the same time the buildings would still block sound from neighbouring streets.
Perhaps in future cities will do this.
I am suddenly day dreaming of a button you can press so that walking through a city sounds like walking through a forested valley on a windless day, as steady snowfall deadens all the sounds around you.
The reverse, a cancelling field for outgoing noise, would be great for practicing music instruments, or guest parties, times when you don't want to disturb neighbors (or roommates). Do the scientists discuss this?
For many instruments the solution is simple: practice on an electronic version. This obviously does not hold for all instruments and not all kinds of practice but it can have a big impact. It has an additional bonus too, you can put on a headphone and cut the outside world off as well so it works in both directions.
I play classical piano, it's really just not the same hehe. At least, the consumer technology is not quite yet there.
This is actually very very important in Singapore. There's multiple highways (sic!) going through the middle of the city. Even on higher floors (say 15 - 20) the constant noise is unbearable if you live on top of one.
I didn't notice many sound isolating walls there either. Guess people who were born there get used to it.
I didn't notice many sound isolating walls there either. Guess people who were born there get used to it.
There are costs to being exposed to high levels of ambient noise though: https://www.euro.who.int/__data/assets/pdf_file/0008/136466/...
Out of curiosity, what's the idea behind including a "sic" parenthetical in an original unquoted piece of writing?
"Sic" means "that's not a mistake". When quoting, it often means "I didn't make the mistake, I faithfully copied somebody else's" but when writing your own stuff, it means "I didn't make a mistake; I meant to write that".
Ok, gotcha. I'm familiar with it (in the "sic erat scriptum" sense) for other people's writing but I've never seen it used in an original writing like that.
Not sure I get it here either, since most cities I can think of have multiple highways going through them, but thanks for the clarification. Always glad to expand my understanding of language.
Not sure I get it here either, since most cities I can think of have multiple highways going through them, but thanks for the clarification. Always glad to expand my understanding of language.
It literally means "thus" which is just another way of saying "Yes, really!"
The other solution here is to put the speakers on the window frame, then you can do some projection etc...
[deleted]
Very timely. So, after boycotting a certain manufacturer for more than a decade on account of their root kit debacle I finally relented and spent some money on a noise cancelling headphone. It works pretty good, the tech has matured and the difference between NC on and off is remarkable. Even a neighbour mowing their lawn or using a chainsaw disappears to the point that I can focus on playing an instrument or writing a piece of code or text.
This was a key element for me in overcoming my insomnia, I used to stay awake at night because it was finally quiet enough that I could concentrate. After identifying that as a key part of the problem noise reduction became a focal point. It has created a new problem: the headphones are so good at this that it is very easy to creep up on me and scare the bejezus out of me when I don't receive any other clue such as a changing shadow or something like that. I'll have to figure out some kind of early warning system for approaching people.
Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money. The article lists one entrant that seems to be a move in the right direction but it does not look like that particular version will be ready for prime time in the near future.
My 'ideal' soundsucker (sonic black hole) is a ceiling mounted device that projects a cone of silence. One possible way in which it could work is by using a phased array of speakers to 'fake' a larger one. But that ideal will likely never be reached due to limitations in physics, imagine the problem as applied to a wavy surface of water: create a wave pattern that cancels out the wavy surface in one circular area without touching the water directly.
Edit: Another - unexpected - benefit is that all the fan noise and other ambient noise in the room I'm in (which I normally don't even notice) also drops by a very large factor with NC enabled.
This was a key element for me in overcoming my insomnia, I used to stay awake at night because it was finally quiet enough that I could concentrate. After identifying that as a key part of the problem noise reduction became a focal point. It has created a new problem: the headphones are so good at this that it is very easy to creep up on me and scare the bejezus out of me when I don't receive any other clue such as a changing shadow or something like that. I'll have to figure out some kind of early warning system for approaching people.
Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money. The article lists one entrant that seems to be a move in the right direction but it does not look like that particular version will be ready for prime time in the near future.
My 'ideal' soundsucker (sonic black hole) is a ceiling mounted device that projects a cone of silence. One possible way in which it could work is by using a phased array of speakers to 'fake' a larger one. But that ideal will likely never be reached due to limitations in physics, imagine the problem as applied to a wavy surface of water: create a wave pattern that cancels out the wavy surface in one circular area without touching the water directly.
Edit: Another - unexpected - benefit is that all the fan noise and other ambient noise in the room I'm in (which I normally don't even notice) also drops by a very large factor with NC enabled.
Amongst the stereotypical conference swag, there used to be a tiny fish-eye mirror with a notch out of the back, so that you could affix it over the corner of your monitor.
Poking around I couldn't find them, but there are rather a lot of tiny fish-eye mirrors being sold to affix to the top or corner of a car rear view mirror (so-called blindspot mirrors). Those should be in roughly the correct size classification.
Poking around I couldn't find them, but there are rather a lot of tiny fish-eye mirrors being sold to affix to the top or corner of a car rear view mirror (so-called blindspot mirrors). Those should be in roughly the correct size classification.
That's neat and low-tech, I may just do that. Thank you!
ThinkGeek used to sell them, but that's not much help since I just discovered that TG no longer exists...
I discovered that before christmas. The Gamestop website is a joke, and ThinkGeek products don't fit well into it.
I really missed them on April Fool's Day this year. Like what's the point of even honoring the day if I don't get to start it by looking for the fake products in the TG catalog? Maybe I should just go back to bed.
I really missed them on April Fool's Day this year. Like what's the point of even honoring the day if I don't get to start it by looking for the fake products in the TG catalog? Maybe I should just go back to bed.
K what? ThinkGeek is gone? Wow, and the website redirects me to EB Games Canada. RIP :(
Any convex mirror would do [1],[7]
[1] https://www.ebay.com/itm/10cm-Diameter-Focal-Convex-Mirror-L...
[7] https://www.amazon.com/Computer-Rear-View-Personal-Security-...
[1] https://www.ebay.com/itm/10cm-Diameter-Focal-Convex-Mirror-L...
[7] https://www.amazon.com/Computer-Rear-View-Personal-Security-...
>used to be
Another victim of open office seating, I'm sure.
Another victim of open office seating, I'm sure.
No, victim of LCD technology. Those little mirror things are only stable on CRTs. If you want em to stay put on a flat screen, you need to glue it down.
> spent some money on a noise cancelling headphone
Which one? I also facing a noise issue with some people that move closer, and getting crazy...
I'm not OP, but I'm sure he's talking Sony, I did a similar boycott (rootkit on Sony music CD's), but recently bought WH-1000XM3 and the NC is phenomenal, battery life is very good; very comfortable and lightweight; not sure I could sleep with them on though.
Can't say about the Sony, but you can't sleep in Bose QC20. Well... you can, and they were pretty comfortable, but they'll very likely break pretty quickly. I went through several pair until I finally twigged that sleeping in them was probably the root cause. Have had fewer problems with the QC20 since not sleeping with them in.
Really, for sleeping just get a good set of passive earmuffs like shooters use. Cost about $20 and will provide 25-30db of real noise reduction (and unlike active NC will also work on non-periodic sounds like sirens or revving car engines). Can double up with foam earplugs too for even more blockage.
FWIW, I use cheap dollar store headphones - $4-5 - with white noise from the phone to sleep. they typically last 1-3 months.
I found that my Bose NC headphones would produce deafening feedback squeal if I rolled onto my side, so beware that possibility.
oh yes, without a doubt, I'd noticed that in some cases, and eventually, if/when they 'crack', it's just a tiny sliver of a hairline crack in one which lets air in and produces that same loud feedback squeal. ouch!
If you sleep on your back or stomach, airpods Pro would be great for you. I side sleep so they’re not an option for me
The batteries on Airpods Pro don't last long enough to cover a night's sleep.
They have blessed me with some blissful naps, however. Possibly their greatest superpower is making robot vacuums disappear.
They have blessed me with some blissful naps, however. Possibly their greatest superpower is making robot vacuums disappear.
I’m going to go out in a limb and say Sony XM3s, since the comment says something about a root kit, which I always associate with Sony. I have the XM3s and they are pretty darn good.
As others have mentioned, the Sony 1000XM3. However, while doing research on this I found a few YouTube videos on it from a channel called Jim'sReviewRoom or similar, where he put microphones inside the headphones so you can listen to what it's actually like, and it seems the XM3s have a huge overemphasis on bass. I ended up buying the Bose NC700 which have a much more neutral sound profile, and slightly better ANC too iirc. They are a bit more expensive though.
I bought WH-1000XM3 and satisfied for superior NC quality but I don't like its sound profile like boosting bass and poor other sounds while boosting bass.
Finally I realized that I need NC for removing some fan noise like HVAC and server but I don't need superior one. I got Beoplay H9i for $300 and satisfied for both. Fewer battery life is cons.
Finally I realized that I need NC for removing some fan noise like HVAC and server but I don't need superior one. I got Beoplay H9i for $300 and satisfied for both. Fewer battery life is cons.
Sennheiser earbuds and hunting earmuffs. Beats anything out there and at a better price.
Oh, I was asking about what he actually buy!
> Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money.
You can tell roughly how far away a sound source is by measuring the curvature of the wavefront, since sound radiates out in a sphere. The farther away you are, the lower the parallax between two sensors.
If you have sensors with 20 cm separation (each ear) then you would need a minimum sample rate of 34.3 kHz to easily correlate sounds within 2 m. With 5 cm separation (to discriminate sounds coming from your sides), you'd need 550 kHz.
Since sound waves are ~10-10,000x lower frequency than that, you need to be able to measure pressure very precisely to distinguish two waves. Rough rule of thumb is 10x, so you'd need up to 1/50,000 precision microphones, or 16 bit. Thats an absolute minimum and you'd probably want ~20 bits.
You might need a DSP and this trick works much better with some high range microphones (electrets are maybe sufficient), but all of that is well within the range of possibility... so I'm kind of surprised nobody has done this yet. I might take a shot at it.
The tricky part is the noise floor, which is only 10-1000x (in terms of voltage from the microphone) below the things youre trying to measure. That means youve got to gather dozens to thousands of samples to determine what should get through, so you need to hear something for up to tenths of a second to decide to let it be audible.
> My 'ideal' soundsucker (sonic black hole) is a ceiling mounted device that projects a cone of silence. One possible way in which it could work is by using a phased array of speakers to 'fake' a larger one. But that ideal will likely never be reached due to limitations in physics, imagine the problem as applied to a wavy surface of water: create a wave pattern that cancels out the wavy surface in one circular area without touching the water directly.
You'd probably want a full network of microphones around your room for this to work, as standing waves will be set up at audio frequencies. It's nontrivial to handle reflections with data from a single spot.
You could do this if you could handle the reflections, but you would need sensors spread around the room (to detect sound before it was already in the cone) and it would only work at a single head height. You'd do it by intercepting the sound, sending opposite waves from above that reached the sound as it propagates across the silenced volume. If you're more than 10s of cm away from the band of silence, the desynchronization will start letting sound through.
It would also be less effective at higher frequencies unless you had head tracking, because the wavelength of sound is not far off from the size of your head.
You can tell roughly how far away a sound source is by measuring the curvature of the wavefront, since sound radiates out in a sphere. The farther away you are, the lower the parallax between two sensors.
If you have sensors with 20 cm separation (each ear) then you would need a minimum sample rate of 34.3 kHz to easily correlate sounds within 2 m. With 5 cm separation (to discriminate sounds coming from your sides), you'd need 550 kHz.
Since sound waves are ~10-10,000x lower frequency than that, you need to be able to measure pressure very precisely to distinguish two waves. Rough rule of thumb is 10x, so you'd need up to 1/50,000 precision microphones, or 16 bit. Thats an absolute minimum and you'd probably want ~20 bits.
You might need a DSP and this trick works much better with some high range microphones (electrets are maybe sufficient), but all of that is well within the range of possibility... so I'm kind of surprised nobody has done this yet. I might take a shot at it.
The tricky part is the noise floor, which is only 10-1000x (in terms of voltage from the microphone) below the things youre trying to measure. That means youve got to gather dozens to thousands of samples to determine what should get through, so you need to hear something for up to tenths of a second to decide to let it be audible.
> My 'ideal' soundsucker (sonic black hole) is a ceiling mounted device that projects a cone of silence. One possible way in which it could work is by using a phased array of speakers to 'fake' a larger one. But that ideal will likely never be reached due to limitations in physics, imagine the problem as applied to a wavy surface of water: create a wave pattern that cancels out the wavy surface in one circular area without touching the water directly.
You'd probably want a full network of microphones around your room for this to work, as standing waves will be set up at audio frequencies. It's nontrivial to handle reflections with data from a single spot.
You could do this if you could handle the reflections, but you would need sensors spread around the room (to detect sound before it was already in the cone) and it would only work at a single head height. You'd do it by intercepting the sound, sending opposite waves from above that reached the sound as it propagates across the silenced volume. If you're more than 10s of cm away from the band of silence, the desynchronization will start letting sound through.
It would also be less effective at higher frequencies unless you had head tracking, because the wavelength of sound is not far off from the size of your head.
Are you planning an experimental setup? I'd be happy to collaborate on something like this. Agreed about the sensors inside the room, you'd need them in more than one place and quite possibly also at multiple levels to be able to figure out the height of the transmitter. Ideally the sensors can be stuck on flat surfaces and go through a calibration routine where they 'chirp' at each other to figure out their relative positions.
Wireless is hard for this kind of stuff due to latency, wires are ugly but practical and for a first run I would definitely prefer a wired solution over none at all assuming it is even possible. An alternative configuration would be a cylindrical shape that is 'noise free', with speakers radiating outward, microphones would be set in a secondary circle around the first one.
I imagine this sort of setup would use a very large amount of computing power to make it work.
Wireless is hard for this kind of stuff due to latency, wires are ugly but practical and for a first run I would definitely prefer a wired solution over none at all assuming it is even possible. An alternative configuration would be a cylindrical shape that is 'noise free', with speakers radiating outward, microphones would be set in a secondary circle around the first one.
I imagine this sort of setup would use a very large amount of computing power to make it work.
Unfortunately I'm underwater on work and with my own stuff for the next many months... Electrical engineering is a time consuming side hustle.
Wireless only has latency if you let it! Plenty of bandwidth outside wifi and bluetooth stacks, and communication over infrared is always an option. You are correct that wifi and bluetooth have way too much latency, though- 50 ms is 15 meters of distance at the speed of sound.
Computing power is surprisingly relaxed. The problem of figuring out what waveforms to output from a line of speakers to create a given distribution of sounds is actually just a fourier transform, funnily enough. Creating a volume of sounds is just a 3d fourier transform. Both are unreasonably fast to compute, given how powerful they are.
If you want to know more about how the math works and what it applies to, check out fourier optics. IMO its one of the coolest natural phenomena.
Wireless only has latency if you let it! Plenty of bandwidth outside wifi and bluetooth stacks, and communication over infrared is always an option. You are correct that wifi and bluetooth have way too much latency, though- 50 ms is 15 meters of distance at the speed of sound.
Computing power is surprisingly relaxed. The problem of figuring out what waveforms to output from a line of speakers to create a given distribution of sounds is actually just a fourier transform, funnily enough. Creating a volume of sounds is just a 3d fourier transform. Both are unreasonably fast to compute, given how powerful they are.
If you want to know more about how the math works and what it applies to, check out fourier optics. IMO its one of the coolest natural phenomena.
Thank you for the pointers. This is all super interesting to me, both because I really am bothered by sound pollution on a daily basis and because I think we have all the parts in place to really deal with this, even if it is anything but a trivial problem. And in a way those are the best problems to be working on.
You can tell roughly how far away a sound source is by measuring the curvature of the wavefront, since sound radiates out in a sphere. The farther away you are, the lower the parallax between two sensors.
That only works in the free field. In a small room (defined as dimensions being larger than ~1/6th to 100% of a wavelength) you no longer have waves, the entire room is pressurized. And as you mentioned, modal behavior is also an issue.
If you're trying to measure the parallax of outdoor (free field) waves, that works in a truly free field, but once you have reflections (from, say, the ground) you have to account for that as well.
That only works in the free field. In a small room (defined as dimensions being larger than ~1/6th to 100% of a wavelength) you no longer have waves, the entire room is pressurized. And as you mentioned, modal behavior is also an issue.
If you're trying to measure the parallax of outdoor (free field) waves, that works in a truly free field, but once you have reflections (from, say, the ground) you have to account for that as well.
You are referring to the reactive near field region, lambda/2pi, which is used for antenna characterization. At the lower end of human hearing (20-40 Hz, using 40) that figure is 1.36 meters. Any room larger than that -literally all of them, unless your ceiling is very low- will propagate a traveling pressure wave instead of just pressurizing.
Further, that figure isn't very helpful for fluid acoustics. Within the equivalent distance you instead would get tons of nonlinear effects, because fluid flow dominates acoustic transmission. In addition to heavily changing transducer loading, things like vorticity also start to dominate. The net effect is that near field issues arise much earlier, at more like a third of a wavelength. Still, only the very lowest audible waves and quite small rooms create non-acoustic behavior.
> once you have reflections (from, say, the ground) you have to account for that as well.
Ish. Only for quite high frequency sounds which change very quickly. Otherwise reflections tend to mostly just overlap with the primary source. For low frequency waves the distance between the microphone and your ears is much smaller than the wavelength, so you don't need to worry about multiple waves very much.
Further, that figure isn't very helpful for fluid acoustics. Within the equivalent distance you instead would get tons of nonlinear effects, because fluid flow dominates acoustic transmission. In addition to heavily changing transducer loading, things like vorticity also start to dominate. The net effect is that near field issues arise much earlier, at more like a third of a wavelength. Still, only the very lowest audible waves and quite small rooms create non-acoustic behavior.
> once you have reflections (from, say, the ground) you have to account for that as well.
Ish. Only for quite high frequency sounds which change very quickly. Otherwise reflections tend to mostly just overlap with the primary source. For low frequency waves the distance between the microphone and your ears is much smaller than the wavelength, so you don't need to worry about multiple waves very much.
> Only for quite high frequency sounds which change very quickly.
I have young kids at home. Those are the exact sounds I’d want to cancel!
I have young kids at home. Those are the exact sounds I’d want to cancel!
That's still < 4 KHz.
> So, after boycotting a certain manufacturer for more than a decade on account of their root kit debacle
TBF It’s not even the same company. Part of the same group, but the entertainment companies are separated from music hardware, have their own heads, their own deals etc.
It’s like boycotting Vox media because of Comcast. It follows a logic, but it feels peculiar.
On your general point, totally agree. There was a company touting to “design” everyday noise by sticking a small module we’d keep in our ear canal, the company seems to have disappeared but I was so sold on the idea. Almost permanent noise reduction, or filtering for nearby voices only would be the dream setup.
TBF It’s not even the same company. Part of the same group, but the entertainment companies are separated from music hardware, have their own heads, their own deals etc.
It’s like boycotting Vox media because of Comcast. It follows a logic, but it feels peculiar.
On your general point, totally agree. There was a company touting to “design” everyday noise by sticking a small module we’d keep in our ear canal, the company seems to have disappeared but I was so sold on the idea. Almost permanent noise reduction, or filtering for nearby voices only would be the dream setup.
If you carry the same brand to benefit from the recognition factor then boycotting all of them is the only consistent action imo.
I get the logic, yes.
Now, Sony has banking, internet provider, insurance, camera sensor, NFC payment companies as well.
Would we also boycott all of these, as well as smartphones that feature a Sony sensor for instance, if the goal is to be consistent ?
I’d totally boycott Sony BMG for life, but I feel it would be the wrong signal to boycott other independent activities, in particular as the headphone devision is one of the last bastion of trying to provide the clearest sound at a fair price, in a world where Beats and Bose are runaway hits.
Now, Sony has banking, internet provider, insurance, camera sensor, NFC payment companies as well.
Would we also boycott all of these, as well as smartphones that feature a Sony sensor for instance, if the goal is to be consistent ?
I’d totally boycott Sony BMG for life, but I feel it would be the wrong signal to boycott other independent activities, in particular as the headphone devision is one of the last bastion of trying to provide the clearest sound at a fair price, in a world where Beats and Bose are runaway hits.
I don’t even consider Sony products. Haven’t since the PS2. They’re kinda like Microsoft for me. I just associate the name with scummy actions and user hostility so I never even evaluate their products. Been that way for well over a decade now and I don’t feel like I missed out on anything. Apparently their mirrorless cameras are pretty good but I honestly can’t imagine owning a Sony thing.
I’m not boycotting Sony, I just associate their name with crappy products.
I’m not boycotting Sony, I just associate their name with crappy products.
I have a Sony CD player from 1984 sitting on my desk, the D5. It's pretty sensitive to scratches on disks (no error correction) but otherwise works flawlessly.
The mirrorless cameras aren't just pretty good, they're the new standard unless you have Canon/Nikon brand loyalty. I can't find the stat right away but IIRC Sony supplies more camera sensors than anyone else for smartphones (or maybe its just the high end ones)
I mean I'm not trying to change your mind, just adding my 2 cents that every piece of Sony hardware I've had was extremely well built and lasted years or decades. I have an old Minidisc player too I dig up every few years to listen to recordings I made back in high school.
The mirrorless cameras aren't just pretty good, they're the new standard unless you have Canon/Nikon brand loyalty. I can't find the stat right away but IIRC Sony supplies more camera sensors than anyone else for smartphones (or maybe its just the high end ones)
I mean I'm not trying to change your mind, just adding my 2 cents that every piece of Sony hardware I've had was extremely well built and lasted years or decades. I have an old Minidisc player too I dig up every few years to listen to recordings I made back in high school.
You probably have a Sony sensor in your phone.
I got burnt by apple's airpods in a very similar way. The unavoidable firmware update made my Version1 airpods useless despite everything else being okay. I now actively avoid Apple products because they seem to not care. Same with the battery related slowing down of iphones. The new version of Airpods also did somehting scummy with the NC being toned down after an unavoidable firmware update.
Also, considering how much these thngs cost, too much money gets thrown out when just the inbuilt lithium batteries wear out eventually. I now avoid buying anything with embedded and unremovable batteries if possible.
Also, considering how much these thngs cost, too much money gets thrown out when just the inbuilt lithium batteries wear out eventually. I now avoid buying anything with embedded and unremovable batteries if possible.
Well, one possible point of a boycott is to send a message to the extent possible. "Infecting users will ruin your brand" is one possible message. The brand's buyers also bought its legacy.
Permanently removing yourself as a customer from a brand does not send a message. It's only good for making yourself feel good. If one wants to send a message, it's imperative to use collective action- organizing or joining an organized boycott. An organized boycott has a specific start and end date and its demands are publicly known. That way the owners of the company can see the dip in their charts.
Well, the people who boycott aren’t silent (see above). Maybe someone younger reading this thread thought “what rootkit?” and looked it up. Maybe now that person won’t buy Sony. I certainly don’t. You know Sony’s marketing research departments are aware that this is a thing. One of the great things about capitalism is consumer choice and the way a negative brand image actually hurts their bottom line and helps their competition. Imagine if Comcast had competitors :)
Same here with the boycott, caved and got some NC headphone and they live up to the hype. Said company have always been masters of audio.
Does anyone else get this weird nauseating feeling from NC headphones? It's been a while since I wore some, but the silence felt... loud.
Not really, but I do get tired of wearing most headphones for prolonger periods... It's also difficult to lay in a pillow to sleep with NC headphones.
Airpods fare a little better, but I'd like something even more improved... if it could somehow let fresh air in and cool my ears a little too, that would be great...
Airpods fare a little better, but I'd like something even more improved... if it could somehow let fresh air in and cool my ears a little too, that would be great...
Here is some info on stuffed ear syndrome https://www.soundstagesolo.com/index.php/features/178-eardru...
Mentioned here: https://news.ycombinator.com/item?id=22078517
Mentioned here: https://news.ycombinator.com/item?id=22078517
Huh, that's very interesting, thanks!
Yes this is a known phenomenon, it's on the rare side but definitely exists. I have it too.
> Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money.
This exists today, it's just not a device, it's building materials. The more sound deadening you want, the more expensive the room will be. It's possible to deaden sound in this manner to the extent that many people feel uncomfortable[1].
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1. https://en.wikipedia.org/wiki/Anechoic_chamber
This exists today, it's just not a device, it's building materials. The more sound deadening you want, the more expensive the room will be. It's possible to deaden sound in this manner to the extent that many people feel uncomfortable[1].
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1. https://en.wikipedia.org/wiki/Anechoic_chamber
Yes, but the entire premise of this article is: can you do this, but also keep your windows open. No amount of sound deadening will help you if you have a window opened to the outside.
I suspect noise-insulated fans that let air in with the window closed will be simpler and cheaper.
There is no such thing. You can have quiet fans, but there are no fans that block noise. It is not possible to do so; the best you can do is long baffling. An example would be central air in an apartment building: the vents are very long and do not join each other until they reach a central point, which helps attenuate sound. This is a very inefficient process, and the baffle has to be much longer than the distance you'd have to stand in a free space to not hear anything.
Could you put active noise cancelling into the ductwork?
sure, but the whole point was not using noise cancellation.
Depends how much air you need to move.
For one person, a baffle of 10x 1cm sheets of plywood with a 2cm air clearance will do wonders (works out to be approx a 30cm cube with a 30x2cm slot at the front and back).
You can push ample air for one into a studio without any audible sound getting through.
For one person, a baffle of 10x 1cm sheets of plywood with a 2cm air clearance will do wonders (works out to be approx a 30cm cube with a 30x2cm slot at the front and back).
You can push ample air for one into a studio without any audible sound getting through.
There are companies that sell these (mostly to keep homes habitable when a new noise source like an airport runway affects them). I don't know how they work, but I'd assume that they pull the air through baffles and/or noise-absorbing material.
Yeah sure but in the meantime there are hundreds of millions of us living in existing housing stock (and many rent), if a room device worked nearly as well as noise cancelling headphones I'd pay $2k for it. That's still fairly cheaper than renovating and soundproofing an entire room.
We should still press for better soundproofing and sound management in new buildings and communities whenever we can.
Yeah that's fair, on the other end I think cities should take noise pollution and reduction seriously. Banning things like fireworks and gas powered leaf blowers can have a bigger impact on mental health than many people realize.
[deleted]
as someone who sleeps with bose qc35s on I have intermittently also used cheap construction hearing protection and found those to be just as effective (with the difference ben that the passive construction headphones do BETTER but the quality of the sound is less calm if that makes sense, the bose are also slightly more comfortable due to being smaller and having less pressure)
I'm assuming one of the biggest things limiting sound cancelling is processing speed? being able to react to changing waveforms as they arrive at the ears
I'm assuming one of the biggest things limiting sound cancelling is processing speed? being able to react to changing waveforms as they arrive at the ears
Processing speed isn't a huge issue anymore.
Fitting both microphones and speakers in the device is the current challenge. The Bose device shows we are very close to solving that too, and the rapid shirking of wireless in-ear headphones is helping.
Fitting both microphones and speakers in the device is the current challenge. The Bose device shows we are very close to solving that too, and the rapid shirking of wireless in-ear headphones is helping.
Maybe the speakers could serve as microphones at the same time that they are driven by measuring their back-emf?
> I have intermittently also used cheap construction hearing protection and found those to be just as effective
I use both (Bose QC35ii and 3M Peltor X5A) and I find the Bose is better in two ways: ear comfort and it doesn't trigger my tinnitus. It seems the Bose lets in just enough ambient sound that my brain doesn't go into a tinnitus-crescendo-loop.
Also, of course, the construction headphones don't play bluetooth audio.
I use both (Bose QC35ii and 3M Peltor X5A) and I find the Bose is better in two ways: ear comfort and it doesn't trigger my tinnitus. It seems the Bose lets in just enough ambient sound that my brain doesn't go into a tinnitus-crescendo-loop.
Also, of course, the construction headphones don't play bluetooth audio.
For me it got to a point where I hate being outside without my headphones.
The silence is pretty addictive.
The silence is pretty addictive.
>I used to stay awake at night because it was finally quiet enough that I could concentrate.
Same here, particularly during a time when I was living in a noisy apartment building. It was particularly difficult for me as I didn't to take sleeping pills since I'm a bit against those things.
>Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money.
One of the first things when I got myself an RTX 2080, was learning how to use the ray tracing APIs to develop an idea similar to what you mention. I was using the rays to model the wavefront of an arbitrary source of sound, and then, given a 3D scene of a "room" or whatever, visualize how this wave was traveling through the space and reflecting over surfaces with different parameters.
The point of this was to see if you could find/predict the spots in a room/house/building where noise is naturally damped. The visualization was very nice to look at as I modeled the wavefront as if it had an exaggerated effect over the diffraction of light on the air. I cannot find it now, but there used to be a 2000s or so tv ad for the Beolab 5 which looked very similar in essence, maybe also a bit like schlieren photography [1].
[1] https://ntts-prod.s3.amazonaws.com/t2p/prod/t2media/tops/img...
Same here, particularly during a time when I was living in a noisy apartment building. It was particularly difficult for me as I didn't to take sleeping pills since I'm a bit against those things.
>Whoever cracks this particular nut without headphones and manages to create a bubble of 2 cubic meters or so that is silent from outside interference will make a lot of money.
One of the first things when I got myself an RTX 2080, was learning how to use the ray tracing APIs to develop an idea similar to what you mention. I was using the rays to model the wavefront of an arbitrary source of sound, and then, given a 3D scene of a "room" or whatever, visualize how this wave was traveling through the space and reflecting over surfaces with different parameters.
The point of this was to see if you could find/predict the spots in a room/house/building where noise is naturally damped. The visualization was very nice to look at as I modeled the wavefront as if it had an exaggerated effect over the diffraction of light on the air. I cannot find it now, but there used to be a 2000s or so tv ad for the Beolab 5 which looked very similar in essence, maybe also a bit like schlieren photography [1].
[1] https://ntts-prod.s3.amazonaws.com/t2p/prod/t2media/tops/img...
.jpg){kind=link}
> One of the first things when I got myself an RTX 2080, was learning how to use the ray tracing APIs to develop an idea similar to what you mention.
I love the hacker ethos here on HN. Most places, we would here about how high an fps a person obtained on their favorite game with the settings cranked up. Here on HN, we hear about using the ray tracing api to model sound. It is stuff like this that keeps me coming back: hearing how people are using tech in new, really cool ways!
I love the hacker ethos here on HN. Most places, we would here about how high an fps a person obtained on their favorite game with the settings cranked up. Here on HN, we hear about using the ray tracing api to model sound. It is stuff like this that keeps me coming back: hearing how people are using tech in new, really cool ways!
HN is more than one thing to multiple people and those things do not have a very large overlap. I'd love it if we could extract out the hackers/makers portion of HN and give it it's own tab so that the threads there would become longer lived.
Did it not occur to you that the word “hacker” is in the name of the site?
which headphones do you use to sleep ?
I have NE headphones but they are too big for me to comfortable sleep with them (I tend to turn in my sleep)
I have NE headphones but they are too big for me to comfortable sleep with them (I tend to turn in my sleep)
Sony's ANC isn't anywhere nearly as good as Bose's. I'm not a fan of Bose for anything other than aircraft headsets but the QC35 I is as good as consumer ANC gets.
> I'll have to figure out some kind of early warning system for approaching people.
I put my sunglasses under my monitor with the lenses facing me and whatever is behind me. A rounded mirror works well too.
I put my sunglasses under my monitor with the lenses facing me and whatever is behind me. A rounded mirror works well too.
[deleted]
> Dr. Lam explained that “in places like Singapore, we want to keep the windows open as much as possible”
I haven’t spent a lot of time in Singapore but the time I spent there had visibility of about 50m from the burning of scrub/jungle in Malaysia and the air quality was abysmal.
I haven’t spent a lot of time in Singapore but the time I spent there had visibility of about 50m from the burning of scrub/jungle in Malaysia and the air quality was abysmal.
It’s unusual for there to be haze. When there odds have it’s awful but it only happened twice, once bad and over mild, in the 4 years I lived there.
Thanks, things must have improved as its 10+ years since I was there and it didn't seem an unusual event then.
They started suing the companies responsible after the 2014 (?) Indonesian forest fires. Seems to have been effective.
Technology for noise cancelling headphones is fairly straight forward. You put a mic near the entrance of the ear and then reverse the wave. The ear is basically a one dimensional sensor in that configuration. Now, take the headphones away then think about what you have to do to cancel noise. You have this two dimensional window in your home that lets through three dimensional sound waves. The best that you can manage is a two dimensional speaker array which is what you see there attempting to create some sort of sound hologram. It’s insanely complex and anyone who thinks that a company who makes good noise cancelling earphones would therefore be capable getting technology like this to work is just very naive. It’s another magic leap. A whole bunch of people who think they are not buying into snake oil when they really are.
Three dimensional speaker arrays are definitely possible, a simple one would be a cube, a bit harder would be a cylinder.
Yes, it is extremely hard. The question is though, can it be done? Phased arrays are insanely hard as well, they do work though.
In the 80's there was a free space noise cancelling demonstration on a cross roads in a major city somewhere, I can't seem to dig up any references to it. IIRC that was a completely analog setup, I have no idea how it worked but they had a volume within which background noise was substantially reduced. I can't stand it when I am 100% sure that I read something but I can't find it.
Yes, it is extremely hard. The question is though, can it be done? Phased arrays are insanely hard as well, they do work though.
In the 80's there was a free space noise cancelling demonstration on a cross roads in a major city somewhere, I can't seem to dig up any references to it. IIRC that was a completely analog setup, I have no idea how it worked but they had a volume within which background noise was substantially reduced. I can't stand it when I am 100% sure that I read something but I can't find it.
Light Field Cameras (with arrays of micro-lenses) also seemed extremely hard (to me), yet Lytro managed to get the tech working at non-laughable resolutions in a small package, so...shrug.
Yes, but we're talking about a device here that's not sitting in front of your window, but makes it look black.
>Now, take the headphones away then think about what you have to do to cancel noise. You have this two dimensional window in your home that lets through three dimensional sound waves. The best that you can manage is a two dimensional speaker array which is what you see there attempting to create some sort of sound hologram.
First, what you be the problem of creating a three dimension speaker array? Sounds totally feasible...
Second, is that really "the best" that we can do? I've read about a mesh of special design that you can put on your window that still lets you see outside and lets air go through, but cancels certain movement/frequencies, cutting off noise.
First, what you be the problem of creating a three dimension speaker array? Sounds totally feasible...
Second, is that really "the best" that we can do? I've read about a mesh of special design that you can put on your window that still lets you see outside and lets air go through, but cancels certain movement/frequencies, cutting off noise.
You’re right, I should have been more explicit. Passive noise cancellation is far superior for a window. I was trying to point out that active noise cancellation is not feasible (not impossible though) because of the extra dimensions and that the engineering behind active noise cancellation headphones is not the same as what it would take to cover a whole window. By several orders of magnitude.
Honestly, people should just drill an extra hole in their walls, add a quiet fan and put a series of passive sound plates and other known geometry to cancel the sound. Or pipe fresh air from the roof.
Honestly, people should just drill an extra hole in their walls, add a quiet fan and put a series of passive sound plates and other known geometry to cancel the sound. Or pipe fresh air from the roof.
A 3D speaker array is completely pointless. A 2D array can already create all possible sound fields.
It's a hard problem. I wonder whether they can combine a specially made window that funnels the traveling of the sound wave to the active noise cancellation mic and speakers to make it easier.
A back of the envelope thought. A quad-pane window with the double-pane at outside to cut down the noise, a middle air gap, and then a double-pane inside. There's an opening at one end of the outside double-pane to allow air to go between the middle air gap and an opening at the other end of the double-pane inside to allow air to flow through. The ANC can be placed along the middle air gap to reduce the noise more.
A back of the envelope thought. A quad-pane window with the double-pane at outside to cut down the noise, a middle air gap, and then a double-pane inside. There's an opening at one end of the outside double-pane to allow air to go between the middle air gap and an opening at the other end of the double-pane inside to allow air to flow through. The ANC can be placed along the middle air gap to reduce the noise more.
air in
=== ===================
| noise -> <- ANC |
=================== ===
air out
First thing: unless that middle air gap is very wide (10+ inches), you've just created a resonant chamber that almost completely negates the sound reducing performance of the two double-pane layers. This is way party walls consisting of two separately framed walls (drywall-stud-drywall-gap-drywall-stud-drywall) tend to be very poor at blocking sounds between units.
There are other issues regarding the impedance mismatch between the outside and middle air gap openings.
As you said, it's a very hard problem.
There are other issues regarding the impedance mismatch between the outside and middle air gap openings.
As you said, it's a very hard problem.
Can the resonant chamber actually help in the sense that it tunes the sound into certain frequency range? Making the job of the ANC easier? Also can the glass material be tuned to reduce the resonance? Music instruments need to be make certain way to take advantage of the resonant chamber effect; any deviation would produce no sound.
In reality noise cancelling headphones don't "just reverse the wave", since that's often not fast or accurate enough (too noisy). Instead it's more like:
mic -> fft -> secret suace analysis and filtering -> unfft -> speaker
A simple filtering would be a high pass filter, to avoid random high frequency sounds from constructively interfering producing more high frequency static.
Just a random tidbit, if you listen to rtings' examples or have a pair yourself I'd suggest playing some different colours of noise to see for yourself!
mic -> fft -> secret suace analysis and filtering -> unfft -> speaker
A simple filtering would be a high pass filter, to avoid random high frequency sounds from constructively interfering producing more high frequency static.
Just a random tidbit, if you listen to rtings' examples or have a pair yourself I'd suggest playing some different colours of noise to see for yourself!
Can the outside world hear in though?
People may forget themselves and lose sense of perspective. I have a bipolar condition where sometimes I'll pace my apartment and yell about anything and everything, if I lived in one of these places I imagine it'd exacerbate things and bother the neighbors too.
People may forget themselves and lose sense of perspective. I have a bipolar condition where sometimes I'll pace my apartment and yell about anything and everything, if I lived in one of these places I imagine it'd exacerbate things and bother the neighbors too.
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I tried making something like this for closed windows out of a pair of broken NC headphones and some surface vibration speakers stuck to the window. It didn't work very well.
This did get me interested though and am curious of what software libraries and solutions are out there for noise canceling. I would very much like to hook a mic and speakers up to a raspberry pi and get some of the road noise reduced. I'm not sure where to start with software though. I know the basic premise is invert the signal coming from the mic and output that. That's not exactly state-of-the-art though.
This did get me interested though and am curious of what software libraries and solutions are out there for noise canceling. I would very much like to hook a mic and speakers up to a raspberry pi and get some of the road noise reduced. I'm not sure where to start with software though. I know the basic premise is invert the signal coming from the mic and output that. That's not exactly state-of-the-art though.
Interesting. I always thought that the window would make a good speaker. So.. what issues did you run into? You say it didn't work very well? Did you account for the delay?
It sounds like this should work...
It sounds like this should work...
I took the NC headphones apart. I added wires to the mic used for noise cancelling and hung it out the window, closing the window around the wires. I added wires to the headphone speakers and connected them to a small amplifier that was hooked up to the surface vibration speakers. It took about an hour to do.
When it was on and NC was engaged, it was actually louder in the room when a car drove by. The counter noise was adding, not subtracting.
It's was a quick and dirty hack. I assumed the physics and algorithm they use requires the mic to be closer to the speakers and gave up. It would have been pointless to try to modify it further. That's why I was hoping there is a software solution that I could actually have a chance of modifying and e.g. fix the delay if that is the problem. Maybe even a ML solution.
When it was on and NC was engaged, it was actually louder in the room when a car drove by. The counter noise was adding, not subtracting.
It's was a quick and dirty hack. I assumed the physics and algorithm they use requires the mic to be closer to the speakers and gave up. It would have been pointless to try to modify it further. That's why I was hoping there is a software solution that I could actually have a chance of modifying and e.g. fix the delay if that is the problem. Maybe even a ML solution.
Yeah should be possible. I am thinking of working on this. Not sure if an ML solution is necessary but it would be cool and would work.
Could this problem be solved with an adequate ventilation system, so there will be no need to keep windows open?
Important distinction: this is an epistemic "can", not a deontic "can".
In other words, they are saying that it is possible to keep your windows open if you want to and still not let noise in--not that you are permitted to cancel the noise, but must keep your windows open anyway.
I had initially thought this would be something about indoor CO2 buildup or something, but no.
In other words, they are saying that it is possible to keep your windows open if you want to and still not let noise in--not that you are permitted to cancel the noise, but must keep your windows open anyway.
I had initially thought this would be something about indoor CO2 buildup or something, but no.
I don't see how it's possible to win ANC against loud, booming, tiny reproductive bits car stereos driving by wannabe cholos because the speaker size to produce phase-canceling mirror sound would have to be 10-12" / 25-30cm and placed probably on 3 sides minimum... say 12 speakers or 24 for all 6 sides. And the SPL of the ANC would need to be sized proportional to the most powerful car stereo one wished to block.
Is it possible to solve it mechanically? Like airtight, soundproof windows for light and S shaped duct padded with acoustic foam for ventilation?
Here's a low-tech approach: fill the window with staggered plastic straws. You don't get much of a view, however, and the airflow would be impeded.
https://www.researchgate.net/profile/Martin_Tenpierik/public...
https://www.researchgate.net/profile/Martin_Tenpierik/public...
For anyone interested in building this DIY on a smaller scale I highly recommend this Tech Ingredients youtube channel's video:
https://www.youtube.com/watch?v=--c0tiIZG6o
This is by far the nerdiest channel I subscribe to and I LOVE it.
https://www.youtube.com/watch?v=--c0tiIZG6o
This is by far the nerdiest channel I subscribe to and I LOVE it.