[Wingman4l7]

Here One earbuds, by the defunct Doppler Labs. Their precursor, Here Active Listening, didn't even stream audio -- they were focused on just augmenting your auditory environment. IMO way ahead of its time, they unfortunately came out before newer, more seamless wireless Bluetooth software stacks and lower energy chipsets that conserved precious battery life. Ultimately, a product with too niche of a demand to survive. Some of their innovations, like audio-passthrough, are common now.

The saddest thing to me is the really innovative stuff, the preset and customizable audio filters -- which would work even better now that earbuds have even more microphones and processing power than they used to -- have yet to be replicated on any newer hardware because no one seems to be interested.