Sama Veda : Shabd is Brahm and "Silence" too is Brahm
Brahm alone is vibrating everywhere.
guramukh naadhan guramukh vaedhan guramukh rehiaa samaaee ||
The Guru's Word is the Sound-current of the Naad; the Guru's Word is the Wisdom of the Vedas; the Guru's Word is all-pervading.
gur eesar gur gorakh baramaa gur paarabathee maaee ||
The Guru is Shiva, the Guru is Vishnu and Brahma; the Guru is Paarvati and Lakhshmi.
~Sri Guru Granth Sahib Ji p. 2
It can be heard without ears. ''
Guru Amar Das tells us, in Raga Bhairon, that Bhakt Prahlad was saved by
It (Shabd) has been the saving lifeline in all the ages,
Prahlad, the son of the demon-king, knew neither Gayatri nor any rituals,
He became one with God through contact with the Shabd.
Though under the sway of the senses, one feels drawn toward the Cosmic Being
by force of the habit acquired in previous births; nay, even the seeker of enlightenment transcends the Shabd Brahm.
The yogi, however, who diligently takes up this practice,
attains perfection in this very life with the help of latencies of many births
and being thoroughly purged of sin, forthwith reaches the supreme goal.
And by slavery to the Mind thou hast forfeited thy human birth;
Without the Master-soul, one remains blind to the Reality.
and remains indescribable all the same. The mind when attuned with the Sound becomes detached