Stillness means witnessing of all thoughts without chattering and wandering of mind ends up into settling down our thoughts with a great force arisen within. It means you have to put aside all thoughts, desires, memories, fantasies, imagination, and dreams. You have to look into existence directly. It is a process where ego keeps on transcending and you are at the center of being where all noises disappear, your self or self get dissolved but innermost being is there which only speaks and deep connection with existence happens.
The more you are silent the more you can understand the secret and mystery of life by creating a great space within to dissolve thoughts of negativity, hatred, fear, darkness etc. You can observe that miraculous things are happening around you from unknown, empty space, and beyond and you can feel intuition and inner guidance.
Silence is heard existentially, only silence can be heard and understood. Words can be heard but only superficially. We are conditioned to understand only words not silence because we are educated in that way, but we have to go beyond words, to reach the wordless space within us.
There are two ways to communicate our truth either through word or silence. Silence always in the form of presence by channelizing energy.
The more you silent the more you can go for internal cleansing to raise the level of consciousness from fear, hatred, jealousy etc. to courage, awakening, enlightenment etc. The more you internally cleansed the more you try to understand the mystery of life.