Every sound you have ever heard was made by something hitting something else.
A string is plucked. Air is pushed past vocal folds. A mallet meets a bowl. Two objects come into contact and the result travels through air to your ear. There are no exceptions β this is simply what sound is, physically.
The Indian tradition accepted all of that, gave it a name, and then made a further claim: that there is another kind of sound which is not produced by contact, does not travel through anything, and is nevertheless heard.
Ahata nada β struck sound. Anahata nada β unstruck.
This single distinction is the architecture of Nada Yoga. Nearly everything else in the tradition is a consequence of it.
The Words
Δhata (ΰ€ΰ€Ήΰ€€) means struck, beaten, hit. From Δ + βhan, to strike.
AnΔhata (ΰ€ ΰ€¨ΰ€Ύΰ€Ήΰ€€) is the same word with the privative prefix an-: unstruck. Not-struck.
The negation is doing precise work. Anahata is not defined as "spiritual sound" or "divine sound" or "subtle sound." It is defined by the absence of a specific thing: impact.
That precision is worth preserving, because it is what makes the term testable rather than decorative. Any sound with a cause you could point to is ahata, however beautiful. Anahata is the residue.
Ahata Nada: Struck Sound
Everything audible.
How it works: contact produces vibration, vibration travels through a medium, the medium reaches your ear.
Its properties: it begins and it ends. It requires a source. It requires air or water or something to move through. It can be recorded, measured in hertz, shared with another person, and played back.
What belongs to it: chanting, mantra recited aloud, kirtan, the tanpura, a singing bowl, a bell, a flute, birdsong, traffic, the sound of your own breath.
Note that this includes every sound used in Nada Yoga practice. All of it, without exception, is ahata.
The tradition does not treat this as a limitation. The Sangita Ratnakara β a treatise on music, which is to say on struck sound β opens with a discussion of nada as manifestation of the absolute. Struck sound is not the lesser category. It is the workable one.
Anahata Nada: Unstruck Sound
How it works: it does not. Nothing produces it.
Its properties: continuous, without beginning or end, not transmitted through any medium, self-existing, heard internally.
Where it appears: the Hatha Yoga Pradipika, the Nada Bindu Upanishad, the Hamsa Upanishad, the tantric literature, and the musicological treatises which distinguish it from ahata explicitly.
The chakra is named after it. The heart centre is Anahata β the unstruck. Not the other way round. The centre takes its name from the sound.
Here is the definitional consequence that resolves most confusion about this topic: if it could be recorded, it would be ahata. By its own definition, anahata nada is not a pressure wave in air. Any physical explanation of it, if successful, would prove it was something else.
That is not a dodge. It is what the category means.
Method and Destination
The most common error is to treat these as two competing options β as if you should be doing anahata practice and chanting is a beginner's substitute for it.
The tradition frames it entirely differently.
Ahata is the method. Anahata is the destination.
You use struck sound β chanting, mantra, a drone, a bowl β to refine attention. Sound is unusually good at this because it can become progressively subtler while remaining continuous, so attention has to refine in order to keep tracking it. The object trains the faculty.
At some point, attention is fine enough to register something it previously filtered out.
This is why the path is continuous rather than a leap. It starts with chanting Om out loud in a room and ends somewhere the texts describe as beyond description, and every step between is a small increase in the fineness of attention.
It is also why the practices in this tradition end by removing the sound. The drone stops. The chanting ceases. The instruction is always to keep listening β because the struck sound was scaffolding, and scaffolding comes down.
What You Actually Hear
This section is the honest one, and it is the reason to read this article rather than a shorter one.
Close your ears with your thumbs right now and listen. You will hear something: a rushing, a low hum, perhaps a high thin tone.
That is your body. Blood moving through vessels close to the ear. Muscle tension in the middle ear. The auditory system's own noise floor, which becomes noticeable once external sound is removed.
None of that is anahata nada, and the traditional texts are clear that the practitioner starts here and must go past it. The instruction in the Nada Bindu Upanishad is explicit: whatever you are hearing, listen for something subtler within it.
So the honest framing is:
What you hear first is physiological. Expected, normal, and not a failure.
It is also not nothing. It is a legitimate object to begin with. It is quiet, it is continuous, it has detail, and attending to it trains exactly the faculty the practice needs.
Whether anything lies past it is what the practice tests. The tradition says yes and describes what to expect. That claim is not the kind of thing an article can establish, and honest teaching presents it as the tradition's account rather than as demonstrated fact.
On tinnitus
This needs saying plainly.
Persistent ringing, buzzing or humming in the ears is a medical symptom with a range of causes, some of them treatable and some of them warranting investigation. It is not the same thing as anahata nada, and it should not be reinterpreted as a spiritual attainment.
If you have persistent ringing in your ears, see a doctor. Particularly if it is new, one-sided, changing, accompanied by hearing loss or dizziness, or pulsing in time with your heartbeat.
Spiritualising a symptom is a way of not getting it looked at. The tradition loses nothing by your seeing an audiologist, and you may gain a great deal.
The Catalogue of Sounds
Both the Hatha Yoga Pradipika and the Nada Bindu Upanishad describe a progression, and they describe roughly the same one.
Early stages β loud and dense: the ocean, thunder or clouds, kettle-drum, waterfalls.
Middle stages β more defined: a drum, a bell, a horn.
Later stages β subtlest: tinkling bells, a flute, the vina, the humming of bees.
Two things about this list matter more than its contents.
The direction is the instruction. Gross to subtle, always. Whatever is currently audible, the practice is to listen for something finer inside it.
The sounds are not the achievement. Both texts make this explicit. They are markers of position, and the instruction attached to every one of them is to move past it. A practitioner who becomes a connoisseur of inner sounds has found an interesting place to stop.
Why the Heart Centre Carries the Name
A detail worth understanding, because it clarifies the whole scheme.
The four levels of sound run from Vaikhari (audible, at the throat) inward through Madhyama (mental, at the heart) toward Pashyanti and Para.
The heart is where sound exists without being produced β where it is present as mental sound with no breath, no contact, nothing struck.
So Anahata chakra is not named after the unstruck sound by association or poetry. It is the location in the subtle-body map where sound stops requiring impact.
The naming is structural, and once you see it the terminology stops being arbitrary.
Practising the Transition
The point where ahata becomes anahata is the whole practice, and it can be worked on deliberately.
Sit in a stable posture you can hold without adjusting.
Chant β nine long Oms, or a mantra, aloud and unhurried.
Move inward β whisper it, then repeat it mentally, keeping the articulation precise as it quietens.
Stop producing. Deliberately, while something is still happening rather than when you feel finished.
Listen. Toward the right ear, as both texts specify. Do not strain.
Do not evaluate. Assessing whether you are hearing anything is an activity, and activity is what is being reduced.
Stay past the point of interest. When something is heard, the instruction is not to examine it. It is to listen for what is finer than it.
Twenty minutes is enough. The transition β the moment your own sound ends and you continue listening into what remains β is the part to protect. Everything before it exists to make that moment possible.
Common Misunderstandings
1. "Anahata nada is a sound you can measure." By definition it is not produced by contact and not transmitted through a medium. Anything a microphone captures is ahata.
2. "Anahata nada is tinnitus." Tinnitus is a medical symptom warranting investigation. What practitioners hear initially is generally physiological β blood flow, muscle noise, the ear's noise floor β and the tradition says to go past it. Do not reinterpret a symptom as an attainment.
3. "Ahata sound is the beginner version." Ahata is the method at every level. Chanting does not become unnecessary; the practice simply extends past it. The Sangita Ratnakara opens a music treatise with metaphysics for this reason.
4. "Hearing the flute or bells means you have arrived." Both texts treat the sounds as markers and instruct you to move past whatever you hear.
5. "The Anahata chakra is where you hear the unstruck sound." The chakra is named after the unstruck sound because it is the level at which sound exists without production. The listening practice in the texts directs attention to the right ear, not to the heart.
Conclusion
Every sound has a cause. That is what sound is.
The tradition names the whole of that category β ahata, struck β and then asserts that if you refine attention far enough using struck sound, you arrive at something that has no cause and is nevertheless heard.
You do not have to accept the second claim to practise. What is available immediately is the method: use audible sound to make attention finer, and keep listening when the audible sound stops.
What you will hear at first is your own body, and that is not a failure. It is the starting position, and the instruction from there has been the same for centuries.
Whatever you are hearing, listen for something subtler inside it.
Everything in Nada Yoga is that instruction, applied repeatedly, until it runs out of room.
Frequently Asked Questions
What is anahata nada?
Anahata nada is "unstruck sound" β sound not produced by the contact of two objects and not transmitted through any medium. It is described as continuous and self-existing, heard internally when attention becomes sufficiently refined. The heart chakra takes its name from it.
What is the difference between ahata and anahata nada?
Ahata is struck sound: all audible sound, produced by contact, travelling through air, with a beginning and an end. Anahata is unstruck: not produced by contact, not transmitted through a medium. Ahata is the method of practice; anahata is its destination.
Is anahata nada the same as tinnitus?
No. Tinnitus is a medical symptom with identifiable causes and warrants seeing a doctor, particularly if it is new, one-sided, pulsing, or accompanied by hearing loss. What practitioners hear when they first close their ears is generally physiological, and the traditional texts instruct them to listen past it.
What do you actually hear when listening for the inner sound?
Initially the body β blood flow near the ear, muscle tension, and the auditory system's own noise floor once external sound is removed. This is expected rather than a failure. The traditional instruction is to keep listening for something subtler within whatever is currently heard.
Why is the heart chakra called Anahata?
Because it is named after the unstruck sound. In the four-level model, the heart is where madhyama β mental sound β exists without breath, contact or production. The centre marks the level at which sound no longer requires impact.
Can anahata nada be recorded or measured?
No, by definition. It is described as not produced by contact and not transmitted through any medium, so anything a microphone captures would be ahata sound instead. This is what the category means rather than an evasion.
How do I practise moving from ahata to anahata?
Chant aloud, then whispered, then mentally, keeping the articulation precise as the volume falls. Then stop producing sound deliberately β while something is still happening β and continue listening, without straining and without evaluating. The transition itself is the practice.