I think all your reports about experiences with various gizmos is very useful. If you try some more, please update.
Regarding operations, a friend whom we have long lost contact with was one of the early "cyber-women" in the USA. She has a genetic ear problem where females in her family lose hearing in adulthood - in her case in her late 30's. Originally she learned sign language and had her kids do the same. Not everyone with the disease becomes completely deaf - some just have impairment.
The original implant in the late 1990's or early 2000's had, if my memory serves something like 90 little electrodes connecting to nerves in the brain. I assume the latest and greatest have many more. She said that when she woke up after the operation, voices were like the movie version of people talking in helium infused atmospheres --- high pitched squeaky. Within an hour she had learned to distinguished the voices of her husband and kids. By the time I met her again after the operation she was already beginning to get something out of music.
In Europe and the UK you see people often enough who have had the operation. Once you know someone who has had it done, you can recognize the equipment fairly easily although it is getting very discrete. One neat feature of the older versions at any rate is that you can unplug your hearing. My friend's microphone equipment for feeding the signal to the brain had a magnetic connection to the implant. Fed up with the conversation? Pull the plug. Want to listen? stick it back on again.
My wife and I call people with this op "cyber-people" as they have direct electronic connection to the brain. Probably 100,000's with the operation already, maybe 7 figures. My friend was in the first 1,000 or so in the US but that is close to 20 years ago now.
I assume the trick in a successful outcome is finding a well experienced surgeon and not an "apprentice" aka intern.