does teaching esl cause brain damage?

Like all ESL teachers I spend rather a lot of time listening to horribly mutilated English. I am frequently expected to sit and listen to people who do not in fact possess any ability to speak the language. They have no vocabulary, no understanding of basic grammar or of the sound system of English. They frequently have nothing to say in fact, and even if they did, do not seem to have any realistic conception of reality or the dictates of logic. Despite all of this they remain convinced that they need an opportunity to "talk." Personally I would prefer that they spent a lot of time with a carefully designed listening program first. In fact I have come to see my job primarily in terms of being an environment provider/creator. If and when I can bring them around to appreciating the necessity for massive amounts of roughly tuned input their English tends to improve rather remarkably. The problem is that it is frequently difficult for me to get them to recognize my expertise in the matter so they continue to show up for class unprepared, yet expecting an opportunity to talk. The resulting noise I am sure is having a negative impact on the very fabric of my mind.