Slashdot Mirror
One-Way Sound Walls Proven Possible
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)."
Sounds like a good use for interrogation rooms...
What's wrong with an ordinary soundproof wall with a microphone on one side and a speaker on the other?
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...
No sig today...
Looks like they finally got around to fixing the fortune database...
No sig today...
- "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!"
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.
"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?
The article describes the proposed theoretical mechanism as a "wave diode" - I wonder if the same principle is applicable to light? I don't know if "light diodes" already exist in some sense, but that seems like a possibly useful component for optical computing...?
Sounds like the Cone of Silence from Get Smart. Lets just hope it works better :-)
a Cone of Silence
"Are they made from real Girl Scouts?" ~Wednesday Addams
Until every recording gets polluted by sounds from the outside.
Laughter from the next room, babies crying, fire trucks passing by etc.
- "If one man can create that much hate, you can only imagine how much love we as a togetherness can create."
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.
I8-D
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.
I all ready dislike your title.
That's active noise cancellation. This is a proposed mechanism that uses materials with nonlinear acoustic properties to accomplish a similar effect passively. Both methods might be suitable for different situations.
You just need a really tiny man to sift through the molecules and sort them by energy level.
I can imagine it might have many perfectly good uses, but how could it possibly be useful to a band? In a recording situation it would be disastrous! It is difficult enough keeping sirens etc. out of the recording area without actually unviting the sounds into the session.
http://www.acetonestudio.com
Can we wrap children up in this new material? It would make my trips outside of the basement a lot more bearable.
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.
I'm not sure what this had to do with sound, but what you're thinking of already exists and it's called a peltier.
Gamingmuseum.com: Give your 3D accelerator a rest.
The "Cone of Silence"!
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.
That is all.
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!
They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance. - Terry Pratchett
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.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
It's called: the irreversibility of impedance! This is why, for instance, a loudspeaker isn't a great microphone, and vice versa.
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...
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.
We can hear the idiots inside but they don't seem to be able to hear us.
oblig...
In this house we obey the laws of thermodynamics.
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.
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a better masturbation chamber...
Thank you, I have now added a one-way hinge to my imaginary pad.
Cwm, fjord-bank glyphs vext quiz
This sounds like it would be brilliant for the military. Contain the sound of a craft inside but allow the occupants to be aware of what is going on around them. That is pretty much a priceless advantage.
AJ Henderson
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
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.
There was a scene like that in Dune.
A material that allows evergy to only pass one way seems like it would defy some sort of law of physics. Imagine a cube made of this stuff that only lets sound in... Would the energy inside the cube continue to build until it erupted in a sonic boom?
Just make a soundproof wall; put some microphones on one side and speakers on the other.
(you'd have to use some basic amplification, otherwise it would work both ways and the speakers would work like mics and vice versa).
Sony's headquarters must be built out of this stuff.
What do I know, I'm just an idiot, right?
"Talk to the hand."
Make a small cube with each wall made of this material so that sound can enter the cube but it can't get out. Next, let it fill up with sound. Take it to the airport, construction sites, concerts, etc...
Then you leave it somewhere with a sign on it that says, "Open Me."
...was a time traveler!
AL: *singing away inside booth*
TIM: Al! Can you hear me?
AL: I can hear you...
TIM: Think about that.
If you're waiting for everybody to agree with each other (or even be consistent with themselves over time) it ain't gonna happen.
Best political-geek satire of the year.
'We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.' RPF
before this is made mandatory in new housing construction. The police will be able to just walk up to your house and hear what's going on inside without you even knowing they're there.
microphone on one side, speaker on the other.
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?
WARNING: Smartphones have side effects--most of them undocumented.
With material like that loudspeakers could be build that won't reflect the sound inside the box back outside through the cone.
One layer of one-way material on the inside, then one sound absorbing layer on the outside.
home
We don't use it because of the unacceptable price, due to high fuel costs.
Well, I might have a way, but it only works on a semi spherical planet in a vacuum.