[snarfy]

I tried making something like this for closed windows out of a pair of broken NC headphones and some surface vibration speakers stuck to the window. It didn't work very well.

This did get me interested though and am curious of what software libraries and solutions are out there for noise canceling. I would very much like to hook a mic and speakers up to a raspberry pi and get some of the road noise reduced. I'm not sure where to start with software though. I know the basic premise is invert the signal coming from the mic and output that. That's not exactly state-of-the-art though.

[sjg007]

Interesting. I always thought that the window would make a good speaker. So.. what issues did you run into? You say it didn't work very well? Did you account for the delay?

It sounds like this should work...

[snarfy]

I took the NC headphones apart. I added wires to the mic used for noise cancelling and hung it out the window, closing the window around the wires. I added wires to the headphone speakers and connected them to a small amplifier that was hooked up to the surface vibration speakers. It took about an hour to do.

When it was on and NC was engaged, it was actually louder in the room when a car drove by. The counter noise was adding, not subtracting.

It's was a quick and dirty hack. I assumed the physics and algorithm they use requires the mic to be closer to the speakers and gave up. It would have been pointless to try to modify it further. That's why I was hoping there is a software solution that I could actually have a chance of modifying and e.g. fix the delay if that is the problem. Maybe even a ML solution.

[sjg007]

Yeah should be possible. I am thinking of working on this. Not sure if an ML solution is necessary but it would be cool and would work.