Is homemade noise cancelling possible using existing hardware and included software/filters?



I'd like to create a higher tech noise cancellation machine (possibly with added white noise) for a room to reduce the sound of snoring from the next room over. I was thinking that by placing a mic, running it through the appropriate hardware and filters within a computer, and then spitting it out a speaker, I might be able to achieve some noise cancelling similar to my bose in-ear noise cancelling headphones.

The two challenges that come to mind are feedback and making the output sound waves 180 degrees out of phase from the incoming mic audio before coming out the speaker. Is this possible? If so, what hardware would includes these sorts of filters in their included software?

Ein Doofus

Posted 2015-10-02T15:27:25.713

Reputation: 113

5There's a reason why you only see this technology in headphones. The reason is basically what you're talking about in your second paragraph. If you can hear a whole room, there's too many decorellated copies of the noise to be able to effectively cancel it. With headphones, you can kind of consider each ear as a single reception point, so it's possible to have a much more accurate model of what sound is passing through the headphones. – Todd Wilcox – 2015-10-02T19:49:03.810

3Sorry, couldn't resist: just amplify that snoring so much it wakes up the source :-P – Michael Hansen Buur – 2015-10-04T15:48:54.877



This is not possible with technology we have at the moment. As far as I know, you would need to cover every square micron of your walls with a mic AND a speaker. The cancellation effect needs to be so precise that you can't just have ONE speaker producing the cancelling wave.

Sound hits walls, and resonates within the wall (between the drywall, along the studs, etc). This creates many places that the sound wave propagates into your room. Essentially the whole wall becomes a speaker, and you need quite a bit of power to cancel a wall sized speaker.

The reason it works with headphones is that they are small, and the sound wave is already funneled into a smaller area, so merely delaying a repeat of the sound taken in is enough.


Posted 2015-10-02T15:27:25.713


Perhaps they can make some sort of resonator that would hook to your walls and vibrate them to cancel the sound someday. That'd be pretty cool. But again, it'd take a lot of energy – None – 2017-08-20T19:00:49.807