In addition, the sentences are very simple, no complex words, nothing unexpected. We can often understand something like, "it's time for lunch now" without understanding more usual sentences that contain names or terms. I, too, "passed" the hearing test for a CI--i.e., I hear "too well" for one even though even casual conversation can be challenging. I know that I guess about half of what I hear, and you can't turn that fine skill off during a hearing test! When the sentences are really simple, there are no distractions (sound or otherwise), in the isolation of a booth you can understand much better than you can in real life. Even in casual settings, someone suddenly introduces a new line of thought, and you struggle until you understand what the topic is.