I have been looking at the middle ear implant technology, not that I can afford it now, but maybe it will all come down in price if they get enough takers.
But the thing that seems to be missing in each case is how to listen to things that come out of localised sound sources, like stethoscopes and headphones. The Envoy at least uses your own ear as the sound source, but that also involves an actual alteration to your middle ear structure. The others have a microphone placed behind the ear. The Soundbridge has an external processor but shows no sign of having a plug available like the one for cochlear implants or Bahas. The Carina is fully implanted, and again there is no sign of being able to purchase a magnetic connection coil so that sound can be filtered into the device.
So, good start and I am guessing most candidates will not be keen to plug in anything visible, but there are so many devices which use the natural ear, how does it work with these devices to receive your amplification from headphones and things?