In plain words
If this noise is loud, where can you hear the sound of God? The more silent you are, the more clearly you hear the sound of God's footsteps. So silence is God. Just once, enquire into it well. Close your ears well. When you close them, Oṃ rises. That is the sound within silence. When you hold the tongue still, that sound arises. That sound is Brahman. So:
She who is Śabda-brahman, who is all that moves and moves not, who is light, who is speech, who is eternal Ānanda, beyond the highest, who is Māyā, who is Śrī.
Śabda-brahmamayī. What sound is that? The very sound within silence.
We must keep silence for at least one hour a day. In that silence we can build up again the strength we have lost. See, all day we toil and work. At night, once we fall asleep, all the senses take rest. Because the senses take rest, we work briskly. That is, the senses need rest. By giving these senses rest, we too feel rested. Śānti of mind itself is the mightiest power. In the language of Vedānta this is called amanaska. Amanaska means that which has no Manas. When are we without Manas? In deep sleep we have no Manas. In dream too there is Manas. The Manas in a dream creates everything for itself. It creates itself. But in deep sleep, in suṣupti, there is no Manas at all. Su-ṣupti. Deep sleep. That is, they called it good sleep. What is beyond these two, the gross and the subtle, is the causal. Suṣupti is the very form of the causal. Then comes the turīya state. That is the deep principle. A mighty power. This is what they called the turīya state. Waking, dream, suṣupti and the turīya state: four states. But many children keep thinking of something even in their sleep. Many do not even sleep. Once these examinations come, they waste all their time on the examinations, without sleeping. We stay awake a whole night and read twenty pages. What use is it? By dawn not even one page is remembered. Why is that? Peaceful sleep is what you need above all. If we study after spoiling our sleep, we will not pass. Sleep. Get up at three o'clock and study. But you must never ruin your sleep. You can go without food, but without sleep it is hard to live.