I will say him that, because of you, others are unable to answer for any questions. It is good to lead in a discussion, but it is too bad, for not allowing others to participate in the classroom discussion.
I will ask him that, if anyone of others shouts loud like you, and so, if you are not able to speak in the discussion, what will you do??
Thus, I will make him to realize his mistake; and, I will advice him that, discussions are should be taken sportive, and no one should shout and get back others from registering their points.
Thus, I will advice him.
Hope this will help you.