'Silence' does not mean merely holding the tongue. The mind should also be given complete rest. When so done, the mind imbibes greater power and greater clarity. It gets refreshed. The power to concentrate gets enhanced. Your poser to concentrate depends on how much empty is your mind. Silence is highly effective in emptying the mind. All great men and sages have practiced long silence. In Srimad Bhagavad Gita, Lord Krishna says "Among things profound, I am silence".
Therefore, let us learn to be silent.
As told by HH Parama Pujya Sadguru Dr. Sri Ganapathy Sachchidananda Swamiji of Avadhootha Datta Peetham Mysore