12 ms·

Noise-canceling headphones without the headphone

203 points by ystad 6y ago

yellow_lead 6y ago
I expected them to be put elsewhere in the plane. For instance, my office has a floor with exposed AC units, and "noise-cancelling"[1] machines next to them that remove most of the sound of the AC. I wonder if something similar could be done for planes. [1] Not sure exactly what the name of this device is.
- Anechoic 6y ago
  Is that noise canceling or is it masking?
- keyle 6y ago
  That "sounds" interesting but why not have a partition or a less loud AC Unit?
- gruez 6y ago
  Do you have a picture of what it looks like? AFAIK room-wide noise cancellation can't work because noise cancellation requires the exact position of the listener to be known, otherwise the sound will not be canceled out and might even be amplified. see this animation: https://en.wikipedia.org/wiki/File:Two_sources_interference.gif https://en.wikipedia.org/wiki/File:Two_sources_interference...., if one of the wave sources is the AC and the other is the noise cancellation machine, only some areas will have no sound, but others will have even louder sound.
  - dannyw 6y ago
    It’s apparently possible on planes, so it could work for offices too. https://www.flightglobal.com/quiet-revolution/31793.article https://www.flightglobal.com/quiet-revolution/31793.article
JBiserkov 6y ago
>wearing active noise canceling headphones for extended periods of time can be uncomfortable and even cause injury Does anyone know what type(s) of injury is this referring to, how long is too long and how widespread/likely it is?
- Anechoic 6y ago
  I suspect the article is referring to things like bruising from tight fitting earcups or maybe muscle strain from the weight of the headset, not something specifically related to the noise canceling function (except perhaps from excess noise caused by ANC circuit malfunction that might cause a temporary threshold shift)
  - rakwoelq 6y ago
    Aftermarket options can be purchased to mitigate discomfort from ear protection equipment. The Sightlines Gel Ear Pads from NoiseFighters is a popular option for earcup replacement. The IceVents Classic Ventilated Headband from Qore Performance is a popular option for headband replacement.
- duxup 6y ago
  Since my son has been remote learning at a desk next to mine I've been wearing noise cancelling headphones a great deal. The skin around ears have been super sensitive due to what I assume is just the natural heat build up from wearing headphones and pressure on skin not used to having pressure on it all the time. The skin is raw and irritated. It's not terrible, but not comfortable for sure and has been limiting how much I can wear any over the ear or even on the ear headphones.
  - jazzyjackson 6y ago
    Huh, as another commenter said, some people are just more susceptible than others but I've worn headphones for many hours a day to no ill effect. There should be no clamping pressure on the ears, the weight should be on the headband. Might be worth looking at different options. Over-ear vs On-ear can make a difference.
ngneer 6y ago
Always great to see development in this domain. IWAENC and Silentium come to mind as the forefront. I hope one day the researchers will realize that they are trying to cancel the wrong source. Instead of cancelling noise external to the human, the real breakthrough will be to cancel the human voice. This will confer privacy and other benefits in areas of increased population density. I would prefer a smartphone to have a feature like that than an incrementally snazzy camera, for example.
- bawolff 6y ago
  > I hope one day the researchers will realize that they are trying to cancel the wrong source I dont think its due to intentionality just that low pitch is easier to cancel than high pitch things like voices.
- PurpleFoxy 6y ago
  I don’t think this is even possible. Noise canceling works by creating reverse waves that hit your ears at the same time. You have to be able to calculate how long it will take for those waves to hit each set of ears and be able to direct sound at them.
  - chii 6y ago
    That's the simple, signal-processing oriented way to noise cancellation. But what if the software/ai is advanced enough to reproduce a sound, but erase a certain aspect of it? Like how photo editing can edit out an object or background? Then the headphones can use a seal to completely block out all noise, and play only the sounds the user selects!
    - tux3 6y ago
      If we could make a seal that blocks out all noise small (and confortable) enough to fit around a headset, we wouldn't need the whole NC setup. Earplugs below my bose headset work wonder to block out anything short of cataclysmic, but it's hardly practical. And I can't exactly play music with those on...
mattmaroon 6y ago
My new Ram 2500 diesel has active noise canceling and is the quietest ICE vehicle I’ve ever been in. Probably quieter than electric vehicles at high speeds.
- sjg007 6y ago
  Not to people outside your truck though..
  - deleted 6y ago
    [deleted]
  - cylon13 6y ago
    That claim was never made, and you don’t know enough about the poster’s needs and circumstances to criticize their vehicle choice in general.
  - mattmaroon 6y ago
    It’s a little on the quiet side for a 3/4 ton truck on the outside. But obviously not going to beat a Tesla in that regard.
  - dghughes 6y ago
    Common rail diesels are very quiet compared to older style diesel engines. Some are so quiet you wouldn't even know it was a diesel. And with DEF you won't even smell the classic diesel exhaust smell. The loud smelling ones are due to modifications and probably also from "deleting" the DEF (which is illegal).
    - mattmaroon 6y ago
      It’s relatively quiet but still has that distinctive diesel sound. It’s the latest Cummins 6.7 and for something that puts out almost 400hp it’s pretty quiet. I’m fairly sensitive to noise so between that and the ANC I’m pretty happy.
    - sjg007 6y ago
ggm 6y ago
Is this a heat engine? Feels like it has to be obeying the laws of thermodynamics and something has to get hot managing the pressure wave density in air. I'm guessing the speaker magnets and coils heat up. Play enough noise, and the system will explode into fire...
- dan-robertson 6y ago
  I think you get destructive interference in some places (the ears hopefully) and constructive interference in other places (hopefully not the ears). So you’re moving energy rather than destroying it
- TylerE 6y ago
  Audio is basically negligible in terms of power. Those massive stacks of speakers at an arena rock show are (in total) perhaps 20kW. The lights use far more. Earbuds can we well south of one watt.
supernova87a 6y ago
I thought this was already in planes, such as Dash 8 (Q400) -- noise cancellation, although for the general cabin, not the individual seat passenger: https://www.flightglobal.com/quiet-revolution/31793.article https://www.flightglobal.com/quiet-revolution/31793.article https://apps.dtic.mil/sti/pdfs/ADA446777.pdf https://apps.dtic.mil/sti/pdfs/ADA446777.pdf (see plots at end)
up6w6 6y ago
Does anyone here already tried ANC on these new true wireless earbuds ? Does a better better isolation always imply to a better sound quality ?
- lights0123 6y ago
  AirPods Pro certainly has much better bass with ANC on, and I'd say overall sound quality too. It also sounds louder, although I'm not sure if that's just perceptual: higher sound levels are fine to me with ANC off, but are unbearably loud with it on. That's in both loud and quiet surroundings.
  - hatsunearu 6y ago
    I've noticed this as well. When I have ANC on in like a grocery store with music playing at a comfortable volume, then turn it off, I can barely hear the music.
cheeze 6y ago
I get 'vertigo' from ANC headphones. This sounds like my personal hell
evross 6y ago
ANC headphones are great for low-frequency (bass) sounds. But with cheap headphones I find I can still hear speech. I think new housing uses mass loaded vinyl to prevent high frequency sounds from passing through walls - perhaps heavy, 1lb or 1kg headphones with ANC are the solution for experiencing real silence in e.g. a busy workspace? Does anyone have an idea if material weight or density is a big factor in sound insulation? Along with air-tight sealing.
- thepostoffice 6y ago
  In general, anything heavy related to headphones = bad. You can get the equivalent of state of the art ANC performance with a pair of passive IEM's that fit properly. Try using memory foam tips if you have trouble with tips fitting your ear shape.
  - bryan0 6y ago
    Yeah I totally agree. I get that people find them uncomfortable, but passive IEM's to me are way more comfortable than a heavy over-ear set which puts pressure against the sides of my skull. The noise canceling is also amazing without any electronics. Only trick is getting really good drivers in such a small space but IEM manufactures have been doing this for decades with great results.
thepostoffice 6y ago
I work in this area. There's a huge runway in front of us for both products and technology. 'Acoustic Holography' has worked for some time, commercial implementations have been few and far between, mostly because what's in the market is already selling boatloads without it. It'll come eventually, there are a few groups dedicated to it. A successful anchor in that space will allow companies to go deeper into applications. Acoustic room splitting, Silence on demand, etc.
- jogundas 6y ago
  Sounds very interesting! Could you direct the interested to your favorite review article or another starting point?
  - thepostoffice 6y ago
    An implementation or variation on this theme is surely the future of in-room audio: https://en.m.wikipedia.org/wiki/Wave_field_synthesis https://en.m.wikipedia.org/wiki/Wave_field_synthesis The math says, if implemented correctly, WFS is better than sitting in the sweetspot of any speakers. Also, there's no sweet spot with this technology.
thadk 6y ago
"So they used a remote acoustic sensing system built around a laser Doppler vibrometer (LDV), which measures non-contact vibrations over a wide range. In their tests, they placed a tiny, jewelry-sized, retro-reflective membrane in the ear as a pick-up for the LDV." These sound curious: these are the devices that three letter agencies have used to suss out sound from glass, aren't they? https://en.wikipedia.org/wiki/Laser_Doppler_vibrometer https://en.wikipedia.org/wiki/Laser_Doppler_vibrometer "Security – Laser Doppler vibrometers (LDVs) as non-contact vibration sensors have an ability of remote voice acquisition"
deleted 6y ago
[deleted]
marcan_42 6y ago
Edit: they cheated, this isn't ANC and will never work as ANC. See below. This sounds pretty fundamentally different from normal ANC. A common misconception is that ANC headphones "predict" the incoming noise and cancel it (and thus "they're good with constant noise but not sudden changes"). In reality they're just hybrid open-loop/closed-loop feedback systems. Specifically, the mic inside the cavity works with the speaker as a closed loop system to equalize the pressure inside in real time. This works for wavelengths smaller than the cavity size, give or take. So there is no prediction, and they don't care whether the noise is constant or not. They just have a given frequency response, and above a certain frequency all you have is passive muffling (no active cancellation). But this can't do that, because the speakers are much further away from the user. So it had to predict to get any kind of decent frequency response. I wonder how they're doing that. A lot of noise sources are uncorrelated and not predictable... Edit: They cheated. They're taking direct feeds from the source loudspeakers, and then all they have to do is track the transfer function to cancel that out from another speaker. This will never work in the real world, where sound sources are not coincident with your microphones (or lack thereof as in this case). Cool research, zero real world application as a true ANC system. I have no idea why they're selling this as ANC. This looks more like a system for computing real time room/response calibration as the user moves around their head. That's valuable, in a completely different use case.
- Youden 6y ago
  The actual study is here [0] and the abstract and introduction do a much better job of describing what the study is actually about. I encourage you to read at least those before you dismiss the research and its real-world applications. TL;DR: The purpose of the research is to try out a new way of figuring out which sound is going into the user's ears, so that it can be cancelled out. Current methods work for lower frequencies but not for higher frequencies. They "cheated" because they're testing one component of the system and the "cheating" component is immaterial to the research they're doing. [0]: https://www.nature.com/articles/s41598-020-77614-w https://www.nature.com/articles/s41598-020-77614-w
  - marcan_42 6y ago
select-all 6y ago
I wonder if it is possible to mount a noise-cancelling device directly on the source of noise, for example, on a circular saw? The frequency of sound waves from a particular tool is pretty predictable and I can imagine a device with a mic or a vibrometer and speakers that clips directly to a tool and suppresses most of noise from this particular source. I've been using ANC headphones since I started woodworking in the garage and it works for me but not for my neighbours. Soundproofing the garage is difficult and not always possible (not when the door is open anyway), so I would pay top dollar for something like this.
- gocartStatue 6y ago
  theoretically, if the saw has constant RPM then just playing back inverted recording loudly would do it. You just need to match them in phase :)
  - kfarr 6y ago
    Yes I've had a similar idea with a condo neighbor with loud bass, it must be possible to have some attachment you put on the wall to cancel it out. That would sell well
- marcan_42 6y ago
  It's a soundfield problem. This only works for wavelengths that are larger than the size of the emitters and the distance between them. And even then it only works well if you can get the emission pattern of your cancelling speaker exactly the same as the source. So, assuming you had a magical beamforming speaker array around your circular saw, you'd still only be able to cancel frequencies around under 1kHz, because there's no way to get the thing in phase above that. This is why noise-canceling earphones have much better active cancellation at high frequencies than headphones, which rely more on passive isolation until lower frequencies. They're smaller.
gala8y 6y ago
I remember, years ago, a video on TED of a guy presenting working technology for generating sound using collapsing waves from multiple sources, so you can have sound limited to desired volume or cancel noise, so you could have silence next to a busy highway, etc. He was boasting high interest from military. His page/name and the video went offline soon after.
validuser 6y ago
To me, it seems pretty obvious this can't work. The cancelling signal from your seat will have to be cancelled by all the other seats and vice versa, creating a feedback loop.
dusted 6y ago
Gosh, if this makes it into airplanes and such I hope there will be a way to turn it off, I've not yet encountered an ANC headset that does not make me dizzy. Sure some sounds are reduced, but they give this strange "pressure" in my head, hard to explain, like being several meters under the water.
qualitypaper 6y ago
I use a pair of bone conduction headphones and have some cheap earplugs. Better than any ANC headphone/earbud I’ve ever had at cancelling noise. You also don’t get that negative ear pressure or buzzing and they can be quite comfortable. I can be in the middle of a construction site or on a plane and not hear a thing. The one drawback is the sound quality but I’m not exactly an audiophile and tbh the newer bone conduction headphones sound fine to me.

203 points by ystad 6y ago

I expected them to be put elsewhere in the plane. For instance, my office has a floor with exposed AC units, and "noise-cancelling"[1] machines next to them that remove most of the sound of the AC. I wonder if something similar could be done for planes. [1] Not sure exactly what the name of this device is.

Anechoic 6y ago
Is that noise canceling or is it masking?
keyle 6y ago
That "sounds" interesting but why not have a partition or a less loud AC Unit?
gruez 6y ago
Do you have a picture of what it looks like? AFAIK room-wide noise cancellation can't work because noise cancellation requires the exact position of the listener to be known, otherwise the sound will not be canceled out and might even be amplified. see this animation: https://en.wikipedia.org/wiki/File:Two_sources_interference.gif https://en.wikipedia.org/wiki/File:Two_sources_interference...., if one of the wave sources is the AC and the other is the noise cancellation machine, only some areas will have no sound, but others will have even louder sound.
- dannyw 6y ago
  It’s apparently possible on planes, so it could work for offices too. https://www.flightglobal.com/quiet-revolution/31793.article https://www.flightglobal.com/quiet-revolution/31793.article

JBiserkov 6y ago

>wearing active noise canceling headphones for extended periods of time can be uncomfortable and even cause injury Does anyone know what type(s) of injury is this referring to, how long is too long and how widespread/likely it is?

Anechoic 6y ago
I suspect the article is referring to things like bruising from tight fitting earcups or maybe muscle strain from the weight of the headset, not something specifically related to the noise canceling function (except perhaps from excess noise caused by ANC circuit malfunction that might cause a temporary threshold shift)
- rakwoelq 6y ago
  Aftermarket options can be purchased to mitigate discomfort from ear protection equipment. The Sightlines Gel Ear Pads from NoiseFighters is a popular option for earcup replacement. The IceVents Classic Ventilated Headband from Qore Performance is a popular option for headband replacement.
duxup 6y ago
Since my son has been remote learning at a desk next to mine I've been wearing noise cancelling headphones a great deal. The skin around ears have been super sensitive due to what I assume is just the natural heat build up from wearing headphones and pressure on skin not used to having pressure on it all the time. The skin is raw and irritated. It's not terrible, but not comfortable for sure and has been limiting how much I can wear any over the ear or even on the ear headphones.
- jazzyjackson 6y ago
  Huh, as another commenter said, some people are just more susceptible than others but I've worn headphones for many hours a day to no ill effect. There should be no clamping pressure on the ears, the weight should be on the headband. Might be worth looking at different options. Over-ear vs On-ear can make a difference.

ngneer 6y ago

Always great to see development in this domain. IWAENC and Silentium come to mind as the forefront. I hope one day the researchers will realize that they are trying to cancel the wrong source. Instead of cancelling noise external to the human, the real breakthrough will be to cancel the human voice. This will confer privacy and other benefits in areas of increased population density. I would prefer a smartphone to have a feature like that than an incrementally snazzy camera, for example.

bawolff 6y ago
> I hope one day the researchers will realize that they are trying to cancel the wrong source I dont think its due to intentionality just that low pitch is easier to cancel than high pitch things like voices.
PurpleFoxy 6y ago
I don’t think this is even possible. Noise canceling works by creating reverse waves that hit your ears at the same time. You have to be able to calculate how long it will take for those waves to hit each set of ears and be able to direct sound at them.
- chii 6y ago
  That's the simple, signal-processing oriented way to noise cancellation. But what if the software/ai is advanced enough to reproduce a sound, but erase a certain aspect of it? Like how photo editing can edit out an object or background? Then the headphones can use a seal to completely block out all noise, and play only the sounds the user selects!
  - tux3 6y ago
    If we could make a seal that blocks out all noise small (and confortable) enough to fit around a headset, we wouldn't need the whole NC setup. Earplugs below my bose headset work wonder to block out anything short of cataclysmic, but it's hardly practical. And I can't exactly play music with those on...

mattmaroon 6y ago

My new Ram 2500 diesel has active noise canceling and is the quietest ICE vehicle I’ve ever been in. Probably quieter than electric vehicles at high speeds.

sjg007 6y ago
Not to people outside your truck though..
- deleted 6y ago
  [deleted]
- cylon13 6y ago
  That claim was never made, and you don’t know enough about the poster’s needs and circumstances to criticize their vehicle choice in general.
- mattmaroon 6y ago
  It’s a little on the quiet side for a 3/4 ton truck on the outside. But obviously not going to beat a Tesla in that regard.
- dghughes 6y ago
  Common rail diesels are very quiet compared to older style diesel engines. Some are so quiet you wouldn't even know it was a diesel. And with DEF you won't even smell the classic diesel exhaust smell. The loud smelling ones are due to modifications and probably also from "deleting" the DEF (which is illegal).
  - mattmaroon 6y ago
    It’s relatively quiet but still has that distinctive diesel sound. It’s the latest Cummins 6.7 and for something that puts out almost 400hp it’s pretty quiet. I’m fairly sensitive to noise so between that and the ANC I’m pretty happy.
  - sjg007 6y ago

ggm 6y ago

Is this a heat engine? Feels like it has to be obeying the laws of thermodynamics and something has to get hot managing the pressure wave density in air. I'm guessing the speaker magnets and coils heat up. Play enough noise, and the system will explode into fire...

dan-robertson 6y ago
I think you get destructive interference in some places (the ears hopefully) and constructive interference in other places (hopefully not the ears). So you’re moving energy rather than destroying it
TylerE 6y ago
Audio is basically negligible in terms of power. Those massive stacks of speakers at an arena rock show are (in total) perhaps 20kW. The lights use far more. Earbuds can we well south of one watt.

supernova87a 6y ago

I thought this was already in planes, such as Dash 8 (Q400) -- noise cancellation, although for the general cabin, not the individual seat passenger: https://www.flightglobal.com/quiet-revolution/31793.article https://www.flightglobal.com/quiet-revolution/31793.article https://apps.dtic.mil/sti/pdfs/ADA446777.pdf https://apps.dtic.mil/sti/pdfs/ADA446777.pdf (see plots at end)

up6w6 6y ago

Does anyone here already tried ANC on these new true wireless earbuds ? Does a better better isolation always imply to a better sound quality ?

lights0123 6y ago
AirPods Pro certainly has much better bass with ANC on, and I'd say overall sound quality too. It also sounds louder, although I'm not sure if that's just perceptual: higher sound levels are fine to me with ANC off, but are unbearably loud with it on. That's in both loud and quiet surroundings.
- hatsunearu 6y ago
  I've noticed this as well. When I have ANC on in like a grocery store with music playing at a comfortable volume, then turn it off, I can barely hear the music.

cheeze 6y ago

I get 'vertigo' from ANC headphones. This sounds like my personal hell

evross 6y ago

ANC headphones are great for low-frequency (bass) sounds. But with cheap headphones I find I can still hear speech. I think new housing uses mass loaded vinyl to prevent high frequency sounds from passing through walls - perhaps heavy, 1lb or 1kg headphones with ANC are the solution for experiencing real silence in e.g. a busy workspace? Does anyone have an idea if material weight or density is a big factor in sound insulation? Along with air-tight sealing.

thepostoffice 6y ago
In general, anything heavy related to headphones = bad. You can get the equivalent of state of the art ANC performance with a pair of passive IEM's that fit properly. Try using memory foam tips if you have trouble with tips fitting your ear shape.
- bryan0 6y ago
  Yeah I totally agree. I get that people find them uncomfortable, but passive IEM's to me are way more comfortable than a heavy over-ear set which puts pressure against the sides of my skull. The noise canceling is also amazing without any electronics. Only trick is getting really good drivers in such a small space but IEM manufactures have been doing this for decades with great results.

thepostoffice 6y ago

I work in this area. There's a huge runway in front of us for both products and technology. 'Acoustic Holography' has worked for some time, commercial implementations have been few and far between, mostly because what's in the market is already selling boatloads without it. It'll come eventually, there are a few groups dedicated to it. A successful anchor in that space will allow companies to go deeper into applications. Acoustic room splitting, Silence on demand, etc.

jogundas 6y ago
Sounds very interesting! Could you direct the interested to your favorite review article or another starting point?
- thepostoffice 6y ago
  An implementation or variation on this theme is surely the future of in-room audio: https://en.m.wikipedia.org/wiki/Wave_field_synthesis https://en.m.wikipedia.org/wiki/Wave_field_synthesis The math says, if implemented correctly, WFS is better than sitting in the sweetspot of any speakers. Also, there's no sweet spot with this technology.

thadk 6y ago

"So they used a remote acoustic sensing system built around a laser Doppler vibrometer (LDV), which measures non-contact vibrations over a wide range. In their tests, they placed a tiny, jewelry-sized, retro-reflective membrane in the ear as a pick-up for the LDV." These sound curious: these are the devices that three letter agencies have used to suss out sound from glass, aren't they? https://en.wikipedia.org/wiki/Laser_Doppler_vibrometer https://en.wikipedia.org/wiki/Laser_Doppler_vibrometer "Security – Laser Doppler vibrometers (LDVs) as non-contact vibration sensors have an ability of remote voice acquisition"

deleted 6y ago

[deleted]

marcan_42 6y ago

Edit: they cheated, this isn't ANC and will never work as ANC. See below. This sounds pretty fundamentally different from normal ANC. A common misconception is that ANC headphones "predict" the incoming noise and cancel it (and thus "they're good with constant noise but not sudden changes"). In reality they're just hybrid open-loop/closed-loop feedback systems. Specifically, the mic inside the cavity works with the speaker as a closed loop system to equalize the pressure inside in real time. This works for wavelengths smaller than the cavity size, give or take. So there is no prediction, and they don't care whether the noise is constant or not. They just have a given frequency response, and above a certain frequency all you have is passive muffling (no active cancellation). But this can't do that, because the speakers are much further away from the user. So it had to predict to get any kind of decent frequency response. I wonder how they're doing that. A lot of noise sources are uncorrelated and not predictable... Edit: They cheated. They're taking direct feeds from the source loudspeakers, and then all they have to do is track the transfer function to cancel that out from another speaker. This will never work in the real world, where sound sources are not coincident with your microphones (or lack thereof as in this case). Cool research, zero real world application as a true ANC system. I have no idea why they're selling this as ANC. This looks more like a system for computing real time room/response calibration as the user moves around their head. That's valuable, in a completely different use case.

Youden 6y ago
The actual study is here [0] and the abstract and introduction do a much better job of describing what the study is actually about. I encourage you to read at least those before you dismiss the research and its real-world applications. TL;DR: The purpose of the research is to try out a new way of figuring out which sound is going into the user's ears, so that it can be cancelled out. Current methods work for lower frequencies but not for higher frequencies. They "cheated" because they're testing one component of the system and the "cheating" component is immaterial to the research they're doing. [0]: https://www.nature.com/articles/s41598-020-77614-w https://www.nature.com/articles/s41598-020-77614-w
- marcan_42 6y ago

select-all 6y ago

I wonder if it is possible to mount a noise-cancelling device directly on the source of noise, for example, on a circular saw? The frequency of sound waves from a particular tool is pretty predictable and I can imagine a device with a mic or a vibrometer and speakers that clips directly to a tool and suppresses most of noise from this particular source. I've been using ANC headphones since I started woodworking in the garage and it works for me but not for my neighbours. Soundproofing the garage is difficult and not always possible (not when the door is open anyway), so I would pay top dollar for something like this.

gocartStatue 6y ago
theoretically, if the saw has constant RPM then just playing back inverted recording loudly would do it. You just need to match them in phase :)
- kfarr 6y ago
  Yes I've had a similar idea with a condo neighbor with loud bass, it must be possible to have some attachment you put on the wall to cancel it out. That would sell well
marcan_42 6y ago
It's a soundfield problem. This only works for wavelengths that are larger than the size of the emitters and the distance between them. And even then it only works well if you can get the emission pattern of your cancelling speaker exactly the same as the source. So, assuming you had a magical beamforming speaker array around your circular saw, you'd still only be able to cancel frequencies around under 1kHz, because there's no way to get the thing in phase above that. This is why noise-canceling earphones have much better active cancellation at high frequencies than headphones, which rely more on passive isolation until lower frequencies. They're smaller.

gala8y 6y ago

I remember, years ago, a video on TED of a guy presenting working technology for generating sound using collapsing waves from multiple sources, so you can have sound limited to desired volume or cancel noise, so you could have silence next to a busy highway, etc. He was boasting high interest from military. His page/name and the video went offline soon after.

validuser 6y ago

To me, it seems pretty obvious this can't work. The cancelling signal from your seat will have to be cancelled by all the other seats and vice versa, creating a feedback loop.

dusted 6y ago

Gosh, if this makes it into airplanes and such I hope there will be a way to turn it off, I've not yet encountered an ANC headset that does not make me dizzy. Sure some sounds are reduced, but they give this strange "pressure" in my head, hard to explain, like being several meters under the water.

qualitypaper 6y ago

I use a pair of bone conduction headphones and have some cheap earplugs. Better than any ANC headphone/earbud I’ve ever had at cancelling noise. You also don’t get that negative ear pressure or buzzing and they can be quite comfortable. I can be in the middle of a construction site or on a plane and not hear a thing. The one drawback is the sound quality but I’m not exactly an audiophile and tbh the newer bone conduction headphones sound fine to me.