Scientists are said to have made a major step forward in ‘cloak of silence’ technology:

Walls of the material could be built to soundproof houses or it could be used in concert halls to enhance acoustics or direct noise away from certain areas.

The military may also be interested, the researchers believe, to conceal submarines from detection by sonar or to create a new class of stealth ships.

I am excited to hear I might someday be able to have silence where I want it, but I suspect this type of control will bring complications. First, there is danger in silence. Sounds have important meaning. Thus other forms of information gathering will need to be relied upon more heavily wherever silence is found. Second, absolute silence is absolute. It will remove the good sounds as well as the bad and thus perhaps create a new need to re-introduce good sounds. This reminds me of “pure” water than usually is far less healthy than clean but naturally occurring water. There are probably many more issues of security here.

The best use I can think of right now is the box of large engines, to help silence vehicles and reduce noise pollution in cities.