Each question though involves three parties: the questioner, the speaker and the rest of the audience. A good talk has a certain rhythm and questions can disturb that rhythm. So how does the audience feel about the questions? Depends on the question.
- Questions that clarify the model or some aspect of the proof. We need these questions to properly follow the talk. When others ask these questions, I learn that I really hadn't understood the model when I had thought I had.
- Questions that argue against the model or results. Usually entertaing but can often degenerate into a long argument. The host needs to become a moderator and has to give one of those one-time nerd jokes that have become standard lexicon: "Take this discussion off-line."
- Questions that point out mistakes. Usually annoying and serves no purpose unless, of course, it takes down the whole proof.
- Questions that prove how smart the questioner is. The most annoying. I cringe whenever I hear a question starting with the word "So".