Does Chanting "OM" Actually Do Anything? A Small Brain-Scan Study Found Something Real — and It Is Not the "Sound of the Universe"

A scanner room in Bengaluru, 2011: twelve people chanting inside a machine

Let's go to a scanner room. Bengaluru, 2011.

Twelve people lie down one at a time inside an fMRI machine at a psychiatric hospital and research institute. And they chant "OM". Out loud. While a scanner tracks, in real time, which parts of their living brains are working.

Listen to where this is happening. Not a retreat. Not an ashram. India's National Institute of Mental Health and Neurosciences, NIMHANS.

And the researchers did something clever. Think about it: if you only scan people chanting OM, how do you know you are seeing something about OM, and not just "any humming noise"? So they had the same people make a completely different sound, "ssss". And they also had them simply rest quietly. Three conditions. Then they compared all three.

Something in those scans is the reason this file exists. But first, there is a popular claim about OM that I have to deal with honestly. Because it is wrong.

First, the words you need

Six ideas. Learn them once and the rest of this file is easy.

Cosmic Microwave Background Radiation (CMBR). The famous leftover energy from the Big Bang. It was discovered by accident in the 1960s by two physicists, Arno Penzias and Robert Wilson, who later won a Nobel Prize for it.

fMRI. A scanner that shows which parts of a living brain are actively working, in real time, by tracking blood flow.

Amygdala. A small, almond-shaped structure deep in your brain that works as your alarm system. It is the part that lights up when you are afraid, anxious, or sensing a threat, real or imagined. An overactive amygdala is a documented feature of anxiety disorders, and it plays a significant role in depression too.

Vagus nerve. A long nerve running from your brain down through your neck and chest into your gut. It plays a huge role in shifting your body out of "fight or flight" stress mode and into a calmer "rest and digest" state.

Vagus nerve stimulation (VNS). Not a spiritual practice. An actual, FDA-approved medical treatment, sometimes involving a small implanted device, used today for treatment-resistant depression and certain forms of epilepsy.

Pranava. OM's traditional name. A popular devotional reading splits it into "Pra", from prakriti, meaning nature, and "nava", meaning new: "the ever-new sound of nature, or of creation itself." The dictionary derivation is plainer: pra plus the root nu, to sound or to hum.

Three claims, three grades

Here is what this file tests. I grade each one now, so you know where we are going.

1. A 2011 fMRI study at NIMHANS found that chanting OM deactivated several brain regions, including the amygdala, in a pattern the researchers said closely resembles vagus nerve stimulation, and the effect did not appear with the comparison "ssss" sound. True. The study design is below.
2. That this proves OM is a cure, or that a twelve-person pilot settles anything. Unsupported. The study is real and peer-reviewed. It is also small.
3. That OM is literally the sound of the universe, proven by the Cosmic Microwave Background. A myth. I deal with it first, before anything else.

One true, one unsupported, one myth. Let's start with the myth.

Clue 1: the exaggerated claim, dealt with first

The claim goes like this. OM is the literal, actual sound of the universe, and this was "proven" when scientists discovered the Cosmic Microwave Background.

I wanted this to be true too. It is a beautiful idea. Here is what the evidence actually says.

The problem is simple. The Cosmic Microwave Background is not sound. It is electromagnetic radiation. Same broad family as light, radio waves and microwaves.

Now listen carefully, because this is the whole thing. Sound needs a medium to travel through. Air, water, something with molecules that can bump into each other and pass the vibration along. Space, for the overwhelming majority of its volume, does not have that. Electromagnetic radiation, unlike sound, needs no medium at all. It is a completely different physical phenomenon. Not a variant of the same thing.

Put it in plain words: you cannot "hear" the Cosmic Microwave Background any more than you can "hear" the colour blue.

So when someone says "an ancient tradition described a primordial vibration" and "physicists detected leftover radiation from the Big Bang" are the same discovery, described two different ways, it sounds satisfying. But it mixes up two categories that do not overlap.

Why am I being so strict about this? Because getting caught making an over-the-top claim makes people distrust the genuinely solid material too. And there is genuinely solid material here. It is the rest of this file.

Clue 2: what OM actually is, and what humans keep discovering on their own

In the tradition this comes from, OM is not just a word. It is treated as a foundational sound that sacred recitation traditionally opens and closes with. An audible anchor, understood as connecting a person, in that moment, to something much larger than themselves.

Now here is the thing. You do not have to accept any metaphysical claim about OM's cosmic origin to notice something true buried in this tradition.

Let me ask you something. Why would people who never met each other, in completely unconnected cultures and religions, land on the same tool?

Because they did. Again and again, people independently arrived at the idea that a single, sustained, resonant sound, chanted, hummed or sung, does something to the state of a person's mind. OM in Hindu and Buddhist practice. "Amen" closing Jewish and Christian prayers. Sufi dhikr chanting. Gregorian chant. And a mother humming to a crying baby, without ever having read a single study about any of it.

When completely disconnected traditions all stumble onto the same basic tool, it is usually worth asking what that tool is actually doing.

There is now a real answer. Back to the scanner.

Clue 3: what the scan actually showed

Chanting OM caused significant, measurable "deactivation" in several specific brain regions. Deactivation is the technical word. In plain words: those regions became less active. Calmer.

And one of those regions was the amygdala. The alarm system.

Think about why that matters. Calming the brain's alarm system is a genuinely big deal in psychiatry.

Now listen carefully, because this is the detail that makes it more than "chanting feels nice."

The researchers specifically pointed out that this pattern, this kind of calming in this region, closely resembles what is seen with vagus nerve stimulation. The same VNS from the word list. The FDA-approved treatment for treatment-resistant depression.

Here is how the researchers think that might work. Chanting OM out loud produces a vibration you can feel around the ears, and they expected that vibration to reach a branch of that same nerve there, the auricular branch. That was their starting idea, not something the scan showed. If they are right, the humming itself, the actual physical vibration, may be doing real mechanical work on your nervous system. Not just giving you a moment of quiet reflection.

Notice the words I am using: "resembles", "expected", "may be". They are the honest hedges this finding needs. I come back to them below.

Clue 4: why this is not just "relaxing for a minute"

You might be thinking: fine, but any quiet moment calms you down. Sit still, breathe, of course the brain settles.

That is a fair thought. It is not what was shown.

Remember the "ssss" sound? The comparison sound did not produce the same effect.

So it is not simply about making noise. And it is not about breath control alone. It was specifically the low, sustained, resonant vibration of a chanted OM that produced this pattern of calming.

That is the twist. Not a vague wellness slogan. A testable, specific claim. And it held up inside an actual brain scanner.

Now the other side, honestly

The sceptic has two points. Let me give them to you in full, because he is right on both.

One: size. Twelve people. One session. One scanner. A pilot study. Small fMRI studies are exactly the kind of work that sometimes fails to replicate. And "resembles vagus nerve stimulation" is a resemblance the authors noted. It is not a demonstrated mechanism.

Two: expectation. The "ssss" comparison rules out noise-in-general. It does not rule out everything else. Chanting a familiar, meaningful syllable carries expectation with it, and expectation shows up in scans too.

Granted, on all counts. I am not arguing with him. A twelve-person pilot is a real finding and a small one, both at once.

On the record: every claim in one place

Here is the whole file, sorted.

True - A 2011 fMRI study at NIMHANS scanned twelve people chanting OM, compared against an "ssss" sound and against quiet rest. - Chanting OM deactivated several brain regions, including the amygdala. - The researchers noted this pattern closely resembles vagus nerve stimulation, an FDA-approved treatment for treatment-resistant depression and certain epilepsies. - The comparison sound did not produce the same effect.

Unsupported - That twelve people in one scanner settle the question, or that this proves OM is a cure. It is a small, early pilot.

A myth - That OM is literally the sound of the universe, proven by the Cosmic Microwave Background. The CMBR is electromagnetic radiation, not sound, and sound needs a medium that space does not have.

What I could not prove

Two things. I will say them as plainly as the true parts.

• That the vibration reaching the vagus nerve is what caused the deactivation. The researchers note the resemblance to VNS. This study does not establish the mechanism.
• That the effect lasts beyond the session, or helps a diagnosed condition. The scan measures what happened during chanting. Nothing more.

Step back for a minute

What follows is my own view.

You do not need to accept any belief system to try this. And for the physical part, vibration that may reach the vagus nerve through the ear canal and throat, you do not need to chant in any particular language or setting for it to possibly still apply.

So in a moment of real anxiety, a slow, low, sustained hum, held for as long as a comfortable exhale allows and repeated a few times, is a free, physical thing you could reach for, alongside whatever else you are doing for your mental health. OM is the one that has actually been studied this way, which makes it a reasonable choice. It costs nothing, and it rests on more than tradition alone.

But be very clear about what it is not. It will not replace a treatment plan for a real anxiety disorder or depression. A twelve-person pilot fMRI study is real, peer-reviewed science and also a small, early study. Not a guaranteed cure. Not a replacement for psychiatric treatment when that is what is needed. If you need that treatment, OM goes alongside it, never instead of it.

What it shows is a specific, measurable, physical effect worth taking seriously. Not a magic word. And not proof of the dramatic cosmic claims some people attach to it.

If you ask me, the honest version of this story was always going to be more interesting than the exaggerated one. Not "ancient India predicted the Big Bang." Something better: a very old, very simple practice turns out, in one small study, to calm the brain in a pattern that closely resembles what modern psychiatry gets by deliberately targeting a nerve with an implanted medical device.

That, I am proud of. And I do not need to inflate it by one inch.

The verdict

OM does something measurable in your brain, and it is not what the internet says it is.

That a 2011 fMRI study at India's National Institute of Mental Health and Neurosciences scanned twelve people chanting OM, compared against an "ssss" sound and against quiet rest; that chanting OM deactivated several brain regions including the amygdala; that the researchers noted this closely resembles vagus nerve stimulation, an FDA-approved treatment for treatment-resistant depression and certain epilepsies; and that the comparison sound did not produce the same effect, is true.

That twelve people in one scanner settle the question is unsupported. It is a small, early pilot.

That OM is literally the sound of the universe, proven by the Cosmic Microwave Background, is a myth. The CMBR is electromagnetic radiation, not sound, and sound needs a medium that space does not have.

What would change my mind? A replication at larger scale finding no amygdala deactivation. Or a physicist showing the CMBR is a pressure wave after all. Neither exists in the record I read.

The universe is not humming. You can. And in one small scanner study, it measurably calmed the brain's alarm system. You decide what to do with that.

Corrections

31 October 2026. An earlier version of this file said OM chanting calms the brain "in a way doctors already use as an actual treatment for depression", and called chanting "zero-risk" and "evidence-backed". The study is a 2011 pilot of twelve people; its authors said the pattern resembles that of vagus nerve stimulation, an approved treatment. It does not show that chanting treats depression. The file now says only that.

2 November 2026. An earlier version of this file explained OM's name, Pranava, as "Pra" from prakrati, nature, and "nava", new, as if that were its derivation. That is a devotional reading; Monier-Williams' Sanskrit-English Dictionary derives praṇava from pra and the root nu, to sound or hum. It said OM opens and closes "every sacred verse"; the classical rule, as in the Manusmriti (2.74), is that sacred recitation begins and ends with it. It said the chant's vibration "appears to stimulate" the vagus nerve through the ear; in the study, that was the researchers' starting expectation, not a finding. And it called vagus nerve stimulation "FDA-cleared"; the US Food and Drug Administration approved the device in 1997, and approved it for treatment-resistant depression in 2005. The file now says so.