Imagine a material that includes the properties of sound cloaking along with light cloaking. Add in EM cloaking, etc, and you have quite a powerful
technology.
Perhaps that technology exists?
Until you find out that answer to that, you can read through this:
'Cloak of silence' design is unveiled
Two independent teams of researchers have come up with a recipe for making special materials that could completely cloak an object from sound.
Although the “acoustic metamaterials” have yet to be made, a third team is now trying to create a real cloak.
These metamaterials promise to guide sound waves around an enshrouded object as if the object wasn’t there. As well as being used to conceal
submarines from detection by sonar, such metamaterials could be used to improve the acoustics in concert halls.
