If the waveform is just slightly out of sync, it should still be partially destructive, right? If a person walks in between, maybe it reduces the cancelation by

If the waveform is just slightly out of sync, it should still be partially destructive, right? If a person walks in between, maybe it reduces the cancelation by a bit for a few seconds, but it should still be quieter than not having any cancelation... I think? I think the correction system would necessarily have to be real time, like regular active noise cancelation already is. The main difference would just be that it has an additional input source (the downloaded waveform) that it can use to assist what the microphone hears. I think normal noise cancelation continuously records for a few milliseconds and then uses that waveform for the cancelation, while continuing to record and update in real time. This would still be that same approach, except it knows what's going to happen the next second because it already has the waveform downloaded.