> There lies the problem. If its some unrelated people discussing stuff that doesn't interest us then its just background noise and get filtered out. But in office space it is exactly the opposite. You sit around with people who are doing similar work and most often what they discuss is directly or indirectly related to you/your-work. This is a problem.

I can't not pay attention to background noise. It doesn't matter how irrelevant it is, or even if it is speech or not. I also always have to be on guard all the time in case some actually does try to speak specifically with me. Thus, I live in constant fear of interruption.