One-Way Sound Walls Proven Possible 177
disco_tracy writes "Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it. The concept — a kind of one-way mirror for sound — seems imaginary, but two Italian scientists recently pushed this kind of sound manipulating technology closer to reality (abstract)."
Uses (Score:3)
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Automotive as well... being able to hear sirens outside the car without broadcasting your Justin Bieber sirens to the rest of us. Nobody needs to hear that.
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This is NEEDED for automotive applications.
The rest of us do NOT want to hear your 1200 watt bass line on whatever it is you're playing.
If we wanted to hear it, we'd be listening to the same CD or station.
And when you drive through my neighborhood and cause the windows in house to rattle.... don't get me started (I know.. .too late).
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Fuck their "Cultural Identity". I don't need my fucking house to shake when they drive by.
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I always wondered if it would be possible to build a huge parabolic acoustic "mirror" that could focus the energy of those 1200 watt bass systems back either to the glass or the eardrums of the driver causing aural devastation. How big would this parabola have to be to get the kind of energy that could do some real damage?
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I like the idea of using science to deal with this, but I think the xkcd approach [xkcd.com] might be more practical -- and more fun.
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Dammit! There's an XKCD for EVERYTHING!!!!
Re:Uses (Score:4, Insightful)
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Hey, that's pretty insightful! Sound gets in, but can't get out. Submarine is almost invisible to sonar.
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Really necessary? (Score:4, Insightful)
What's wrong with an ordinary soundproof wall with a microphone on one side and a speaker on the other?
Re:Really necessary? (Score:5, Insightful)
Where would we be if people were happy with what they had? There's probably all kinds of situations, and even new inventions, that could use this that we can't even think of at the moment.
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Another poster already mentioned it, but it truly bears repeating. Having that car blasting out their music completely silenced but still able to hear a police siren.
From the article, this is not limited to glass at all. In fact, the article does not even indicate that the material is translucent at any point either.
Something else to consider. Take two of these and slap them together in a sandwich and you know have sound proofing to a fairly extraordinary level in something that is likely to be only a pe
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Yea, for example, what would you do during an extended power outage, with no batteries, solar, or handcrank ?
That silly microphone/speaker idea wouldnt be any use then !
I heard of a new invention too, a movable two way sound resistance wall, with optional visual transparency.
They call them windows.
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Awesome! Then I wouldn't have to work on a saturday!
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Re:Really necessary? (Score:4, Insightful)
They missed the obvious use case. Think of the Children!
Parents can hear kiddie outside when he wants a cookie, but kiddie can't hear the grownup sounds inside the bedroom.
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Or flip it around. Parents don't have to listen to kids. Kids can be scarred for life. It's a win/win! Somehow...
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What's wrong with an ordinary soundproof wall with a microphone on one side and a speaker on the other?
That's like saying why do we need one way mirror when we can just build a wall and put a video camera on one side and a monitor on the other? I'm sure there will be cases when something like this would be useful.
Re:Really necessary? (Score:5, Interesting)
This would be material based and not require additional power?
It would be great for those baby-rooms they used to have in movie theaters. The people inside could hear the movie without the audience hearing the screaming kid.
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... or they could just install speakers inside the baby rooms.
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Lots of reasons (Score:4)
The same reason why a 1 way mirror is better in some applications than a video camera on one side of a wall with a monitor on the other.
On possible use is in security. People can avoid cameras, and small unseen microphones are not directional. Airports, casinos, police stations, and other security heavy areas will certainly have a use.
Imagine the CIA setting up a room for foreign dignitaries. The dignitaries sweep the room for bugs. But unknown to them, the floor of their room is a 1 way sound barrier, with agents sitting below with directional microphones pointed at the ceiling underneath each room.
Imagine a submarine with a section of the vessel being a 1 way sound room where large microphones reside. All other walls are sound deadened except 1 outside wall. More equipment could sit there than any outside array of microphones, listening for enemy ships... but without an outside sonar signature, and without worrying about hearing internal noises.
Even naturalists would love it. Imagine a retreat in a forrest where every outside wall was 1 way, making it sound like you weren't even in a building, but the animals were not disturbed by the sounds you make snapping pictures and talking.
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That's where the Cone of Silence is useful in situations like what you've described.
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You're assuming the sound would remain directional, which may not be the case. Indeed, I would expect the sound to be projected perpendicular to the surface. ... and it will probably not be as general as you expect. It will be a long way (if at all) until it would look like anything other than what it was.
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That is done in studios currently, but I think the main downside it requires electricity and someone usually has to push a button to turn it on (in my experience). Not really sure how effective it would be in a studio, though, unless you want a lot of natural reverb. Incidentally, I used to have a room set up with sound absorbing tile for that exact reason, but that all got torn out in a remodel a few years ago (it was in really crappy condition, or in my wife's words, was "fuggly and has to go"). I actuall
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Sounds like you need to tell your wife to STFU and let you have your hobbies. Unless hers are fair game for your shooting-down as well, that is.
(of course, find a nicer way to say it)
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I'm not sure this would be of any use in a recording studio. Typically they use monitors, and it's not because of the wall. The reason for the sound proofing is because the audio engineer is more interested in what they've got on tape than what's actually being produced. Because ultimately that's what they're going to have available when they go to master the CDs, not the actual sound that's being produced.
You really wouldn't want to turn it around either, because you don't want to have to find completely s
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What's wrong with an ordinary soundproof wall with a microphone on one side and a speaker on the other?
Yeah, we wouldn't want any improvements in sound-dampening technology.
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Band... (Score:5, Funny)
Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it.
They can't be a very good band if they can hear somebody talking in the next room while they're playing...
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I am not sure quality and volume are necessarily equivalent. Actually, I can attest that I have heard quite a few very loud, yet horrendous bands on any given Monday night at the Rat. (if you recognize the club, you're probably old too...)
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Not only that, but they've got the use case backwards. The proper way to set it up is so that everyone else hears the band, but the band can't hear any of the complaints from the neighbors banging on the walls and yelling at them.
Re:Band... (Score:5, Funny)
Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it.
They can't be a very good band if they can hear somebody talking in the next room while they're playing...
Do you have any idea how hard it is to find an amp for an air guitar?
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Pff, they're everywhere... you just have to know one when you see it.
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<quote><p>Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it.</p></quote>
<p>They can't be a very good band if they can hear somebody talking in the next room while they're playing...</p></quote>
Maybe the drawback is it amplifies sounds on the other site... or you can only hear someone if they speak vuvuzela.
Joke Variant Unlocked (Score:1, Interesting)
- "You have a banana in your ear!"
- "I'm sorry, what?"
- "YOU HAVE A BANANA IN YOUR EAR!"
- "I'm sorry, I can't hear you, you're on the wrong side of the wall!"
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"...please call the Bananaphone."
I can all ready do that (Score:1)
Although the acoustic technology remains theoretical, the researchers think that it can be built. Lepri cited optics, saying that nonlinear photonics is a well-developed field now.
Couldn't i just sound proof a room, put a few microphones outside the room send the signal in to the room. Doing it passively is cool but there is no way it would be cheaper then some soundboard a microphone and a speaker.
Huh? (Score:4)
"Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it."
How does this wall mean the musicians will hear the talking over their own music? Is there one-way sound air coming soon too?
Re:Huh? (Score:5, Funny)
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"Imagine a room where a band is playing. Neighbors can't hear the music, but if someone outside the room is talking, the musicians can hear it."
How does this wall mean the musicians will hear the talking over their own music? Is there one-way sound air coming soon too?
They're just trying to explain the concept in very simple terms. Read the abstract instead if you're going to be pedantic.
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There's that, but there's also the question of why that would be desirable anyways. I assumed that meant between sets, but even that doesn't seem particularly useful. If you've genuinely blocked the sound from penetrating in that direction the people on the other side of the wall shouldn't have anything relevant to say.
Big Deal (Score:1)
Wave diode applicable to light? (Score:4, Informative)
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Re:Wave diode applicable to light? (Score:5, Interesting)
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No... a one-way mirror doesn't allow light to pass in only one direction. It passes, and reflects, light equally in either direction. The trick is to make it dark enough on one side that you can't see your own reflection, and bright enough on the other side that they can't see you because their reflection is too bright.
I hope it works. (Score:1)
Ever since I was a kid I've dreamed of having a hot/cold pad. It only lets heat go through it one way, cold side painted blue, hot side painted red. Put it around your soda or beer can blue side in, it cools off your drink, remove when it's just right. Put it around your coffee or soup red side in, it heats it up.
It would probably need a special holding case otherwise your backpack would catch on fire while carrying it. :-)
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Peltier cooling devices need power, though, and tend to amplify the heat output quite a bit more than you'd expect.
Example: Something like this product: http://www.frozencpu.com/products/2408/exp-01/245W_Potted_Peltier.html [frozencpu.com]
Disclaimer: I like FrozenCPU, but I'm not affiliated with them. Just using it as an example of a real-world, purchasable Peltier device, with comments that explain it in a bit more detail.
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t would probably need a special holding case otherwise your backpack would catch on fire while carrying it.
No, just fold it in half so that the cold sides were facing out.
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No, fold it in half with the hot sides facing out. That way there's a limited amount of heat trapped inside it for it to move out; when the middle reaches absolute zero it simply can't continue moving heat across (actually, it'd undoubtedly be an asymptotic approach, but that's beside the point).
What you suggested would cause the inside to get hotter and hotter, making your backpack colder in the process. And even whatever magical material you used to make the hotpad has to have a melting point somewhere...
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Thank you, I have now added a one-way hinge to my imaginary pad.
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oblig...
In this house we obey the laws of thermodynamics.
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he wants a passive device. What he's talking about is a thermal diode. thermal and acoustic diodes would be very similar (audible vs phonon frequency matching being the primary issue). if they didn't violate the 2nd law, that is.
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That's right. And if you could have a cut off temperature like certain diodes with voltage then you could use it as a temperature regulator and build it into walls.
Get Smart (Score:2)
Let's build... (Score:1)
Not like a one-way mirror. (Score:2)
This isn't really like a one-way mirror. With a one-way mirror light travels through it and reflects from it the same in both directions. It's just that the amount of light reflecting from the bright side is much much greater than the 'signal' which comes through from the dark side.
This is apparently a true 'one-way' material.
Can we make this mandatory? (Score:2)
Can we wrap children up in this new material? It would make my trips outside of the basement a lot more bearable.
Better use: recording studio (Score:2)
Unfortunately for the neighbors, the band is more likely to install the walls the other way around. Making a room that can be monitored from the outside (by a sound engineer/producer) while rejecting outside sounds would be ideal for a recording studio.
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Unfortunately, that still doesn't answer the question of "Why would you want the sound to pass through a wall prior to recording it?"
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You wouldn't; the pickups would be inside the sound chamber, not outside. That's the whole point of rejecting outside sound from the space, get a clean recording of what happens inside.
That being said, though, I think the right question for a skeptic would be "wouldn't a completely soundproof room and earphones for the producers/engineers be a better solution than this?", to which the answer is, "yeah, maybe". After all, that's what we're doing now in good studios, and the job's getting done. I'm sure if
Nothing extraordinary; happens all the time. (Score:2)
It's called: the irreversibility of impedance! This is why, for instance, a loudspeaker isn't a great microphone, and vice versa.
Here is a simple DIY way to do it. (Score:2)
Put the band in a tightly soundproofed room. Put some microphones outside of the room, and amplify the sound from the outside into loudspeakers in the room.
See? Microphone --> amp --> speaker. One way signal with off-the-shelf stuff.
Washington DC's been surrounded by this for years. (Score:5, Funny)
We can hear the idiots inside but they don't seem to be able to hear us.
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If you're waiting for everybody to agree with each other (or even be consistent with themselves over time) it ain't gonna happen.
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Best political-geek satire of the year.
This makes for (Score:4, Insightful)
I dunno (Score:3)
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You mean kind of like what a laser does with photons?
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Almost all materials have differing levels of transmission and reflection of waves. It has to do with impedance difference at the interface.
The trick here is there are two interfaces. Air-to-wall on either side. What they've done is to make the impedance differences dfferent on the two sides (low-to-high on one side and balanced on the other side, I would guess), and make it work for a broad spectrum of frequencies.
The question is how much attentuation you get in the transmissive direction. If they're c
This should be easy with 19th century technology (Score:2)
(you'd have to use some basic amplification, otherwise it would work both ways and the speakers would work like mics and vice versa).
It could make a fun gag item... (Score:3, Funny)
Then you leave it somewhere with a sign on it that says, "Open Me."
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So Al Borland... (Score:2)
...was a time traveler!
AL: *singing away inside booth*
TIM: Al! Can you hear me?
AL: I can hear you...
TIM: Think about that.
Is this so hard to belive when... (Score:2)
Buckaroo Banzai can hear the sound of someone crying within the same room while guitar amps and drums are going full blast?
Quote: Is anybody out there not having a good time?
Perfect for loudspeakers (Score:2)
One layer of one-way material on the inside, then one sound absorbing layer on the outside.
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Looks like they finally got around to fixing the fortune database...
Try to... (Score:2, Insightful)
not very obviously break the production site by dumping the entire fortune file out with every page.
World to Slashdot calling, it would like you to know about little tiny things called "testing environments". You should learn about them.
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World to Slashdot calling, it would like you to know about little tiny things called "testing environments". You should learn about them.
And exactly where do you think you are now? The best testing environments look exactly like the production environments. Taco is such a smart dude!
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Nice try. I hear that in the test environment they still haven't ironed out the occasional post trunca
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World to Slashdot calling, it would like you to know about little tiny things called "testing environments". You should learn about them.
I hear Aperture Science is pretty experienced with these things. I recommend contacting them with any questions you have about testing.
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I can think of a lot of uses for it, mainly in the research/testing fields:
1: Observing wild animals without worry about noise spilling over.
2: Outer walls of a building to keep sound in (so the neighbor doesn't call 911 because of that awesome drum solo at 11:00 PM), while being able to hear what is going on outside.
3: As stated above, keep the obnoxious music inside the car, while still being able to hear the motorcycle in the blind spot.
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That's not how that works. If you've got the obnoxious music inside the car, there is no way that you could direct this technology where you'd be able to hear the motorcycle. You could however direct it so that they could hear you're obnoxious music, but you couldn't hear them.
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Perfect for porn consumption! Just don't accidentally install the wall the wrong way around.
I would take it one step further and shape the wall into a parabolic dish pointed at my neighbor's house!
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