How is the feeling of hearing sound of silence?

It cannot be explained in words if actually somebody is able to experience the core sound of silence. It is like explaining the pain. Pain can only be felt and can be addressed as heavy or light as far as the nature of pain is concerned. Similarly, the sound of silence can only be felt and it would not be an easy task. It would be an extreme and in-depth mode of meditation practised over a long long period of time. You become the whole, you are the whole existence, it is discovering the divine soul. So to be able to hear the silence through meditation is a blessing.