I don't know if it's the same as the Bose "Hearphones", but my Sennheiser PXC550 have what Sennheiser call a TalkThrough mode. It pauses the music (if it's playing) and uses the microphones to let through sounds on the wavelengths of speech. If you combine it with noise cancelling, it definitely makes it easier to hear people in noisy environments. Looks weird to talk with over-ear headphones on, though. To be honest it feels a bit creepy to hear what people say while it looks to them like you're listening to music and can't hear them.
Hm I'm not sure, I haven't used it for that so I don't know. It's mostly designed so that you don't have to take them off for a quick interaction, so it's definitely not optimized for your use case. For example, the fan noise in our server room is at least partly in the frequency spectrum it lets through, so it's useless there.
