According to an Entrepreneur columnist, no speaking creates the illusion that you are intelligent. When we had an employee that never asked a question we thought it was odd, because we expected lots and lots of questions. When we did not get them, we looked deeper into the work and found that there was little understanding and a lot of errors and inconsistencies. Silence does not mean intelligence; sometimes it means fear, or intimidation and no understanding and shyness.
I have had one on one meetings with people who love to use pauses in the conversation to draws others into filling the empty space with the first thing that comes to their mind. When this is done to me I view it as a test of stamina. With one person, I would get a little smile on my face and look directly at him with the smile and slight nod. This broke him into filling the void. So I would always win. He stopped meeting with me a while back, good thing he was not a direct client.
Silence can be a tool. If you are not talking hopefully you are listening to those who are speaking.