Silence has always been in eulogized. Krsnadasa Kaviraja Goswami, a renowned saint, has said that silence is one of the 26 qualities of a devotee of the Lord. Many people keep maun brat – on a specific day they do not speak anything. This can help one to control their tongue but what about the mind. We just do not speak through our tongue but we also speak through our minds. Our mind is a chatter box. There is not even a single moment when we can say that our mind remains calm and silent. Mentally we keep on talking to ourselves, we keep on contemplating on things like money, job, family, friends, politics, opposite sex, cricket match and so on. There are some meditation schools who teach to mediate on something null & void. According to them this would help to silence our mind. But this is practically impossible. As a soul we are ananda - mayo bhayasat - pleasure seeking - and mediating on void will not provide us any pleasure. It will make our life boring and later frustrating.
Real silence is to stop contemplating & stop speaking about unnecessary subject matters which disturbs our mind. Instead of this we should contemplate on & speaking about spiritual topics which take us closer to God. Prahlad Maharaj has listed sravanam and kirtanam as the two processes of devotional service. Sravanam means to hear about Krishna and kirtanam means to always speak about Krishna. These two processes will take us closer to God. So, instead of wasting our precious time and energy thinking and speaking about unworthy subject matters let us utilize each moment of our life thinking and speaking about Krishna. Thinking about Krishna also gives us lots of pleasure. It opens the door for everlasting happiness.