Does CI Work? – 1

Ruth asked a question about Sabrina’s greetings questions to start class, and it made me wonder if we are possibly overrating how much our students learn.
My question has to do with how many hours we have for CI vs. how many hours are necessary. This is one of those devil’s advocate types of questions: In the time we have with our students, which is such a small fraction of what is really need for actual visible gains, can our kids can be said to be learning as much as we think they are, especially the unmotivated ones? A related question is, “Should we focus more on output in class?”
I know – my question is not clear. But I just am wondering if kids trained in CI are learning as much as we think they are. Another way to ask the question is “When we are rocking a story, is their unconscious mind really hearing and registering all the language being aimed at them or are they registering understanding through visual cues and in other ways?”
Just thinking out loud.