The trouble with this is that it will create a dependence on the technology. Deaf people will not bother to learn properly how to lip read, instead relying on the easier technology. If/when it fails, they'll be fucked, thrown into a world of incomprehensibility, much older than they were previously and with a much more difficult time to learn to lip read (as the brain is less adaptable with age). I could see that it would be very handy for something like university lectures, if the audio pickup was taken from the existing hearing aid audio loop. So that you could understand what a speaker was saying who was too far away to lip read, or not necessarily always facing you. But, it's a technology not without costs. Like all technologies, it has tradeoffs. If I were in that situation, it might be a useful tool, but you'd want to maintain a backup.