[Uhrheber]

That's actually not a bad idea, a lot of people already have headphones with integrated microphones and processors.

Noise cancellation headphones could be easily transformed into hearing aids with a change of the firmware. In fact, they could be excellent hearing aids, because they probably have more computing power than the average professional hearing aid.

[sannee]

Bose apparently already does something like this. See Bose Hear.