Sound Vs Anti-sound?

Ive got a pair of earphones which have a button on them that cuts out background noise. Im guessing it samples the noise then sends out an inverted version of it to cancel it out, thats only a guess though. It works quite well. Just wondering if something like this would be hard to implement in a whole room, cancelling out noise from outside like traffic or noisy neighbours. How feasible would this type of approach be?

Maybe a speaker somewhere in the room you want soundproofed thats playing the anti-noise from mics which are placed near the source of it.

Thanks

Hi megamox. Great idea :lol: . there was a posting on this a while ago.

Unfortunately though, it would be impossible, unless it is done in a room that is specifically meant for that kind of thing. The reason being is that there are so many different things in the room that bounce the sound waves all over the place, so you would end up with echoes and stuff that would totally throw it out of wack.

What you would probably need (this is a guess) is a padded room, to absorb the sound waves, so it doesn't echo, with nothing in it.

The infamous "Fenton Silencer" :lol:
yet surprisingly this old sci-fi story by AC Clarke that details
the exploits of a young scientist interested in acoustics has
given the world much to think about.
**broken link removed**


Active Noise Control Experiment to try
at home with your PC speakers
https://www.val.me.vt.edu/

You don't need a computer and software to demo acoustical cancellation.
Just connect one of your stereo speakers out-of-phase like all speaker systems in hi-fi equipment stores. When they are facing each other, especially very close, the low frequencies disappear.