I'm into AI but not into sound, so I might be saying something stupid here, but I think using something like this for very high volume like concerts would be possibly outright impossible, but, even if not, certainly quite dangerous and therefore not commercializable.
My understanding is that to "mute" a sound, you need to inject another wave that is exactly the opposite, with the exact same volume and in perfect sync, so that the two waves interfere destructively. However, in general but especially in AI, you can never guarantee 100% accuracy. If you use this technology to "silence" a background fountain, and something goes wrong, at worst you get a lot of noise that make you grimace and remove them. If at a concert with 100+ dB of music you get an error and your headphones start producing a similarly loud, but not perfectly aligned noise right into your ears, you probably won't have the time to remove them before damaging your hearing system.
In general, I think that having a tool that drives 100+ dB straight into your head is probably not a wise idea :-)
You could probably achieve the same outcome by combining two approaches though. Use traditional timing and phase management that existing noise cancelling headphones do. Then, using the data from that same set of microphones use AI to extract the conversation of interest (maybe using timing differences from left/right to determine who's "in front" of you) and inject that as the thing to overlay on top of the inversion. This way there's no risk of AI error on the noise cancellation and you can rely on existing solutions.
Even putting 50db of sound in the opposite direction might help take something from the volume of a nightclub to the volume of a refrigerator [1]. Not perfectly muting it, but perhaps good enough for many scenarios.
Disclaimer - I also have no technical experience of sound
It probably wouldn't work for in-ear setups. However, I'd you have over the ear headphones with good passive noise canceling (35db) then you would need less of the active canceling (65db) to make it quiet and safe.
You can get earplugs with ~30 dB reduction and builtin in-ear monitors. Slap some microphones and such on the outside, and you can probably work with it.
My understanding is that to "mute" a sound, you need to inject another wave that is exactly the opposite, with the exact same volume and in perfect sync, so that the two waves interfere destructively. However, in general but especially in AI, you can never guarantee 100% accuracy. If you use this technology to "silence" a background fountain, and something goes wrong, at worst you get a lot of noise that make you grimace and remove them. If at a concert with 100+ dB of music you get an error and your headphones start producing a similarly loud, but not perfectly aligned noise right into your ears, you probably won't have the time to remove them before damaging your hearing system.
In general, I think that having a tool that drives 100+ dB straight into your head is probably not a wise idea :-)