Effectiveness of a sound manipulator in different environments?

Question

So I’m a super villain, I’ve captured a hero with the ability to manipulate sound and I’m having a hard time keeping him from escaping.

This super human can create and manipulate sounds at just about any frequency he wants. He can hold low amplitudes for a long period of time, but very high amplitude sounds seem to be very taxing on him, and he can only use short pulses which seem to have about the same energy as the sonic boom from a jet at his maximum.

You might think I could just use ear plugs, but since sounds are vibrations that means he can vibrate the walls of his prison until it shakes apart. I’ve not been able to find a way to directly suppress his abilities, and he doesn’t seem to be running out of energy any time soon.

So I need to know what kind of materials will reduce the effectiveness of his powers or even cancel them out completely. It would also be helpful to know what materials I should keep away from him at all costs. Whoever has the best answer can have extra cookies after I take over the world!

Answer 1

Let me start by quoting a famous movie:

Here you can find the answer to your question. Put your prisoner in a vacuum after having covered all the walls of his cell with aerogel.

He won't be able to convey sound through air, and even if he manages to touch the surface of the cell he will be much limited in transmitting a decent amount of energy.

Oh, also vacuum will likely kill him, so it is up to you if you want to provide him with a breather and a suit.

Answer 2

1. Vibranium

This Marvel Universe material absorbs all sound vibrations. If the superhero's powers is limited to appendages like hands, vibranium powercuffs might be sufficient; otherwise, a cell made from this metal might be required. The metal is very rare and incredibly expensive, especially the Wakandan variety which has the above property, but there are alternatives.

An artificial variety that mimicks Wakandan vibranium has been developed. It is less stable but should still be sufficient. Artificial reverbium might also do: this material amplifies and projects sound waves, ending in an explosion. A cell of this material would prevent power use since the hero would kill themselves.

A good example of such tactics would be Magneto's no-metal cell in X2: X-Men United (2003 film). Note that these types of imprisonment attempts always fail due to story reasons.

2. Power Nullifiers

A standard trope of superpower universes, these items negate power use. They tend to exist as cuffs or collars, but room-sized or larger pieces of equipment also exist. Genoshan mutant-power-nullifying collars, the Brainiac domes in the DC Comics Convergence storyline, or the "Detention Room" in Sky High (2005 film) come to mind.

3. Soundproofing

Your captured superhero seems versatile but not overly powerful. Normal tech soundproofing might be enough to contain them. An anechoic chamber might be sufficient as a prison cell. Noise cancellation generators might also work, causing destructive interference and cancelling the power-generated sound waves. All sorts of dampening and absorbent materials can be found today; a supers universe might have a lot more variety and of higher quality.