Brain-computer interfaces for the disabled have been tried. There's plenty of academic work on the topic. For some people who are completely paralyzed the technology allows them to communicate by typing 1 character per second.
Right, I found that information at the time, but wasn't convinced this was the best achievable performance for such individuals (let alone price-performance), considering what should be possible with consumer-grade BCIs + Dasher.
I still can't convince myself that this is the best they can do. Personal project time?
I'm thinking about writing a more substantive post about how humans work and how we can work better, a little like this one. As is common with these sorts of things, once I started to do research and pull on various threads, it turned out that the field was pretty deep and would require time to understand. But in the meantime, I just thought I would link to this video of someone programming using only their voice.
As I suffer with symptoms of carpal tunnel syndrome, this is of particular interest to me. Once I watched it I decided to start looking at different voice recognition software so that I could still get some work done while typing less. I'm happy to say that even the default software for speech recognition which came with windows is actually very able and accurate. I dictated almost this entire post using that software.
As far as I can tell, Dragon Naturally Speaking is the gold standard in voice recognition software. It does come with a pretty hefty price tag, but it may be worth it if you have serious repetitive stress injuries, or as a preventative measure if you're someone who spends a lot of time at their computer. And if that doesn't work, chances are good your computer has adequate software pre-installed.