A Shield Against Sound.
Most recent answer: 5/9/2017
- Seth (age 28)
Perak, Malaysia
Hi Seth,
We already have invisible sound shields, of sorts. They are already available commercially: noise-cancelling headphones.
The principle is simple: measure the incoming sound wave, and broadcast (using standard speakers) the exact same wave, but out of phase. The waves superpose, or add up, as all waves do; since they are out of phase, they cancel exactly.
However, I'm pretty sure this could only work within a closed space, like headphones or an airplane cockpit.
If you wanted to shield something in free space, I think you'd need some sort of cloak made of bulky composites, as you said (see wikipedia: "soundproofing"). I can't think of anything which isn't somewhat bulky that reflects or absorbs a high percentage of sound.
Cheers,
David Schmid
(published on 06/26/2013)
Follow-Up #1: reducing noise
- Jack Thorne (age 86)
Glen Ellyn, IL USA
That does sound like a miserable situation. We probably aren't good people to give advice. Maybe a lawyer would be better.
The people in the house behind ours occasionally get very noisy. A thick stand of tall bamboo helped reduce the sound a bit. That takes a few years to grow, and even then can't be counted on to be thick every year. Maybe another reader will have a good idea.
Mike W.
(published on 05/09/2017)