Scientists in Germany Create Acoustic Invisibility Cloak

Isn't sound an audible phenomenon rather than a visible one?

Where's the red pen? <sigh>

What would be the purpose of such a 'cloak'?

Unless it works underwater.

It doesn't sound like it.

I can imagine such a system being analogous to a visible light cloak where the light is picked up by a small sensor on one side of cloaking object and transfered to the other side and emitted at the same wave length. By making the sensors and emitters very small they could be placed side by side. Light striking one side is transmitted to the other side.

In the case of an acoustic cloak a very sensitive pizo device is used to detect and cancel the acoustic signature on the impinging side of the cloak and then transfer the electrical signal generated by the pizo to another pizo opposite the receiving side. The signal could be amplified to compensate for losses in the cloak circuits.

I would imagine the longer the wave length the greater the effectiveness of the cancellation with a small time offset occuring at the beginning and end of the cancellation. Perrhaps the higher the freqency and shorter the pulse length the more difficult it would be to cloak.

As a counter measure to sonar such methodology could be used to offset range determination.

Gavilan

http://www.youtube.com/watch?v=V6p5mbp_M98

Milo

Not only do we fail to see Harry Potter; now we can't hear him, either (optic inaudibility?)

Hear no Evil !

Render all nagging and ranting inaudible. Take control of your life with a personal muting cloak. Make that 'phone call from a rock concert ; render the cabbie silent....Cloak now only $50.00....Hood $5000.00...

But seriously, we should have all heard/ read something about proposed acoustic anti-personnel weapons by now. This seems to be the proposed body armour.....

if the Cloak fits...

I don't get it.

That's the Cone of Silence from Get Smart. The people conversing within can't hear each other but everyone outside hears what is being said just fine.