It is the place where the right words can come together. Without silence, the torrent of words becomes coercive for both speaker and listener. The words are automatic, unconsidered, expressing thoughts and feelings the speaker himself is not fully aware of. They run in ruts, responding in the same old ways to the same old triggering remarks. Silence is the dark soil through which the seedleaves of a new understanding may push through to the light.
Silence is essential to the proper management of a conversation.
Only when I am silent can another contribute in a balancing way. Only when the whole group regularly punctuates its discourse with silences is there a chance for the conversation to be formed consciously as a communal work of art instead of running on wildly under its own power. I'm not sure to what extent it is possible. But each contributor can at least exercise such a discipline within himself, weighing each remark before submitting it. The familiar advice about writing a response, then waiting a day before mailing it, is often appropriate.