The sound is noted in the first word in the Guru Granth Sahib – ੴ, Ik Oangkar. The syllable "Oang" is the sound that was created whilst the universe was created.
The sound is documented in the first word of the Guru Granth Sahib – ੴ, Ik Oangkar. The syllable "Oang" was produced when the universe came into existence.