Is a cochlear implant a brain-computer interface? · Grey Matter

In the broad sense, yes: it is a computer that writes into the nervous system, and with about a million users it is by far the most common neural interface.

Is a cochlear implant a brain-computer interface?

In the broad sense, yes: it is a computer that writes into the nervous system, and with about a million users it is by far the most common neural interface. It only writes, and it stimulates the auditory nerve in the inner ear instead of the brain itself, which is why it is usually called a neural prosthesis. It still sets the benchmark for every implant in the brain, because it shows how much a few channels can achieve once the brain adapts to them.