Due to recent visitors who may not know about cochlear implants, I'll explain a bit about the sound:
As I was late-deafened, I 'remember' sound so I can compare how it is to normal hearing.
When it is first switched on, there is noise. As in my video, I was spoken to but all it sounded like was one high pitch, no understanding at all. I was expecting actual speech so that was a bit of a shock.
Coming out of the office after activation, when playing with my mobile phone, I could hear the clicking of the keypad! It was the everyday type noises that I recognised almost right away and I spent weeks revelling in all those little things that people take for granted, like the click of the light switch being turned on and off and the pffssshhhttt noise when opening soft drink.
It took about 2 weeks before I could understand speech without lipreading. I believe that is really fast, some CI recipients who are born deaf my never get to that point.
I could not live without my implant. It has helped me so much. Saying that, it is not like 'real' hearing. It can still sound a bit hollow and robotic. I am still hard-of-hearing because I don't understand everything. I find it very difficult to hear when there is a lot of background noise. I still prefer to have subtitles when I watch TV and movies.
I couldn't use the phone when I had hearing aids, I could not understand a thing. But now I can pick up the phone and talk to my loved ones and that is priceless :)