In some schools of yoga, sabda is an
esoteric concept of the sound current that vibrates throughout all
creation. The sound can be heard internally or externally through
speech, mantras or music. Sabda is referred to as the inner sound,
the audible life stream or the word. It is also believed to be the
essence of God.
In the Upanishads, sabda first appears
in an explanation of the two kinds of Brahman: Shabda Brahman (with
sound) and Ashabda Brahman (without sound).
Surat Sabda yoga is a spiritual
practice in the Sant Mat tradition (meditation on inner light and
sound) and other related traditions. The goal of this type of yoga
is union of the self with the Absolute/Supreme Being, or realization
of the true Self. Surat Sabda yoga believes that at the birth of the
universe, sound vibrations from the creative Force were sent out into the abyss.