Most people know Om as a sound heard at the start of a yoga class. Almost no one is told what it actually means, or that a complete Upaniá¹£ad — the MÄṇá¸Å«kya — exists for the sole purpose of explaining it, sound by sound, state by state. This is that explanation, sourced from the original texts.
Om is usually presented to the world as decoration — a symbol on a T-shirt, a sound to hum before a workout ends. This does the Sanskrit tradition a disservice. In the Upaniá¹£ads, Om is treated as the single most important sound a human being can utter, and an entire text, the MÄṇá¸Å«kya Upaniá¹£ad, exists to explain precisely why.
The explanation is not mystical hand-waving. It is a structured argument, built sound by sound, that uses Om as a map of consciousness itself — moving from ordinary waking awareness through dreaming and deep sleep to a fourth state the text calls Turīya. Every claim below is drawn directly from primary Sanskrit texts, not from secondhand spiritual paraphrase.
Written in Devanagari as à¥, and transliterated as either Om or Aum, the syllable is phonetically composed of three sounds: A (as in “calm”), U (as in “put”), and M (a closed, humming nasal). In Sanskrit phonetics, A and U combine by a standard sandhi rule into the single vowel O — which is why Aum and Om are the same sound written two ways.
The MÄṇá¸Å«kya Upaniá¹£ad — one of the shortest Upaniá¹£ads, at just 12 verses — takes this three-part structure and assigns philosophical meaning to each part, plus a fourth meaning to the silence that follows the sound. This is the four-part analysis that follows.
Drawn directly from the MÄṇá¸Å«kya Upaniá¹£ad, verses 3 through 7.
A
The sound "A" (as in "car") represents VaiÅ›vÄnara — the waking state, in which consciousness is directed outward through the five senses and experiences the physical, external world. This is ordinary daily awareness: seeing, hearing, working, eating. The MÄṇá¸Å«kya Upaniá¹£ad places it first because it is the state every reader already knows directly.
U
The sound "U" represents Taijasa — the dreaming state, in which consciousness turns inward and experiences a mental world built from impressions (vÄsanÄs) left by waking experience. Dreams feel completely real while they last, which the Upaniá¹£ad uses to make its central point: waking reality, too, may be a state of consciousness rather than an independent fact.
M
The sound "M" represents PrÄjña — dreamless deep sleep, a state with no object of experience at all, yet not nothingness. A person who has slept deeply reports on waking, "I slept well, I was aware of nothing" — meaning some undivided awareness was present to register the absence of thought and dream. The Upaniá¹£ad treats this everyday, universal experience as direct evidence of a substratum consciousness beneath the other two states.
Turīya
After A-U-M is spoken, there is a silence in which the sound continues to resonate and then fades. The MÄṇá¸Å«kya Upaniá¹£ad calls this TurÄ«ya — literally "the fourth" — a state that is not a fourth item alongside the other three but the awareness in which all three occur and which remains when they cease. It is described as Å›Äntam, Å›ivam, advaitam: peaceful, auspicious, non-dual. This is the philosophical destination the entire text has been building toward — and it is the reason Om is chanted, not merely read.
oṃ ity etad akṣaram idaṃ sarvam — "Om — this syllable is all this." The Upaniṣad opens by stating that the whole of manifest reality, past, present, and future, and whatever is beyond the three periods of time, is Om.
— MÄṇá¸Å«kya Upaniá¹£ad, Verse 1
tasya vÄcakaḥ praṇavaḥ — "The word (vÄcaka) that expresses Īśvara (the supreme, unafflicted consciousness) is the praṇava," i.e., Om. Patañjali follows this in sÅ«tra 1.28 by prescribing its repetition (japa) with reflection on its meaning as a direct method of yogic practice.
— Yoga Sūtras of Patañjali, 1.27
oṃ ity ekÄká¹£araṃ brahma vyÄharan mÄm anusmaran — Krishna tells Arjuna that one who departs the body while uttering the single syllable Om, and remembering Krishna, attains the supreme goal. The GÄ«tÄ treats Om as the sound-form of Brahman itself, not a symbol referring to something else.
— Bhagavad GÄ«tÄ, Chapter 8, Verse 13
The ChÄndogya Upaniá¹£ad opens its entire text with an extended meditation on Om under the name udgÄ«tha — the syllable sung at the start of Vedic chant — calling it "the essence of essences," rasatama, the most essential of all essential things.
— ChÄndogya Upaniá¹£ad, 1.1.1
In 2011, a research team at NIMHANS (National Institute of Mental Health and Neurosciences, Bengaluru) published a pilot fMRI study titled “Neurohemodynamic correlates of ‘OM’ chanting” in the peer-reviewed International Journal of Yoga. Comparing brain activity during Om chanting to a control condition, the study reported deactivation in limbic regions — including the amygdala, hippocampus, and cingulate cortex — areas associated with emotional processing and the brain's stress response.
Other published work in the same journal has examined heart rate variability during Om chanting relative to silent sitting, reporting measurable autonomic nervous system changes consistent with a relaxation response. As with most mind-body research, these are small pilot studies and should be read as such — not as proof of any specific health claim — but they represent genuine, citable, peer-reviewed inquiry into a practice that is nearly 3,000 years old.
What the research does not need to prove is the philosophical content of the MÄṇá¸Å«kya Upaniá¹£ad — that is a separate question, addressed by the text on its own terms, not by neuroscience. The two lines of evidence, textual and empirical, simply happen to converge on the same ancient practice.
Om did not stay within a single tradition. Buddhism absorbed it directly into its own mantra literature — most famously in Om Mani Padme Hum, chanted across the Tibetan Buddhist world. Jainism incorporates Om into its own symbolic and mantric practice. Sikhism opens its scripture, the Guru Granth Sahib, with the phrase Ik Onkar(“One Om, one reality”) — a direct incorporation of the same Sanskrit sound into a distinct theological framework centuries later.
This is a pattern seen across Sanskrit's influence generally: a single precise concept, coined in the Vedic and Upaniá¹£adic tradition, proves durable enough that entirely separate religious systems adopt it on its own terms, rather than replacing it.
🕉ï¸
Three sounds for three states of experience everyone already has. A silence for the awareness that holds all three. That is the MÄṇá¸Å«kya Upaniá¹£ad's claim, made in twelve verses, roughly 2,500 years ago.
Sources: MÄṇá¸Å«kya Upaniá¹£ad (trans. Swami Gambhirananda, Advaita Ashrama) · ChÄndogya Upaniá¹£ad · Yoga SÅ«tras of Patañjali, SÄdhana PÄda · Bhagavad GÄ«tÄ, Chapter 8 · Kalyani et al., “Neurohemodynamic correlates of ‘OM’ chanting,” International Journal of Yoga (2011)
Om is a Sanskrit syllable the MÄṇá¸Å«kya Upaniá¹£ad treats as a symbol for the whole of reality and consciousness. Its three sounds — A, U, M — represent waking, dreaming, and deep sleep. The silence after represents a fourth state, TurÄ«ya, the awareness underlying the other three.
In Sanskrit phonetics, "a" and "u" combine by a sandhi rule into the single sound "o." Aum and Om refer to the same syllable — Aum shows the three component sounds separately, matching the Upaniṣad's own verse-by-verse structure.
The MÄṇá¸Å«kya Upaniá¹£ad, just 12 verses long, is devoted entirely to Om, mapping its sounds to four states of consciousness: VaiÅ›vÄnara (waking), Taijasa (dreaming), PrÄjña (deep sleep), and TurÄ«ya (the transcendent fourth).
Yes. A 2011 NIMHANS pilot fMRI study in the International Journal of Yoga found limbic-region deactivation during Om chanting. Other published research has measured heart rate variability changes. These are small pilot studies, not proof of specific health claims.
Om originates in the Vedic and Upaniá¹£adic tradition and is central to Hindu philosophy, but Buddhism (Om Mani Padme Hum), Jainism, and Sikhism (Ik Onkar) all directly incorporate the same Sanskrit sound into their own traditions.
ॐ
Stories from the Rāmāyaṇa, Mahābhārata, and Bhagavad Gītā. Grammar, shlokas, etymology. 10 minutes a day. No sign-up needed to begin.
Continue exploring India's knowledge heritage