Where did you get the idea that it's "a world full of chipmunks?" The people who hear chipmunks, Minnie or Mickey Mouse or whatever hear that at activation or during the early weeks/months. I never even had either at activation. I had everyone in their own voices.
Most people who get a CI wind up with better hearing than they had with a little hearing and a hearing aid.
I am a CI user, your description is correct.