Noise-canceling headphones without the headphone
Edit: they cheated, this isn&#x27;t ANC and will never work as ANC. See below.<p>This sounds pretty fundamentally different from normal ANC. A common misconception is that ANC headphones &quot;predict&quot; the incoming noise and cancel it (and thus &quot;they&#x27;re good with constant noise but not sudden changes&quot;). In reality they&#x27;re just hybrid open-loop&#x2F;closed-loop feedback systems. Specifically, the mic inside the cavity works with the speaker as a closed loop system to equalize the pressure inside in real time. This works for wavelengths smaller than the cavity size, give or take. So there is no prediction, and they don&#x27;t care whether the noise is constant or not. They just have a given frequency response, and above a certain frequency all you have is passive muffling (no active cancellation).<p>But this can&#x27;t do that, because the speakers are much further away from the user. So it had to predict to get any kind of decent frequency response. I wonder how they&#x27;re doing that. A lot of noise sources are uncorrelated and not predictable...<p>Edit: They cheated. They&#x27;re taking direct feeds from the source loudspeakers, and then all they have to do is track the transfer function to cancel that out from another speaker. This will never work in the real world, where sound sources are not coincident with your microphones (or lack thereof as in this case). Cool research, zero real world application as a true ANC system.<p>I have no idea why they&#x27;re selling this as ANC. This looks more like a system for computing real time room&#x2F;response calibration as the user moves around their head. That&#x27;s valuable, in a completely different use case.