तOne syllable, heard.
An interactive film · the science of sound
Photosensitivity warning: Flashing visuals, bright pulses and rapid zooms.
Every lesson in chanting begins the same way. Someone says a syllable, and you say it after them. The whole exchange takes less than a second, and almost all of it is invisible: a tongue meeting the teeth, a column of air set ringing, a wave too fast to see, a membrane in the ear that moves less than the width of an atom.
This film slows that second down. It follows one akṣara, त (ta), the first sound of the Sundara Kāṇḍa, out of a reciter’s mouth and into a listener’s, and it labels every scale it passes through with its real size: from a person seated on the floor to a single atom, about ten orders of magnitude.
The voice comes from the opening verse of Anukriti’s Sundara Kāṇḍa track Dṛṣṭā Sītā. The pitch on screen, the timing of the release and the resonances of the mouth are all measured from that recording.
Sundara Kāṇḍa 5.1.1
ततो रावणनीतायाः सीतायाः शत्रुकर्शनः ।
इयेष पदमन्वेष्टुं चारणाचरिते पथि ॥
tato rāvaṇanītāyāḥ sītāyāḥ śatrukarśanaḥ ·
iyeṣa padam anveṣṭuṃ cāraṇācarite pathi
Then the tamer of foes resolved to seek the trail of Sītā, carried off by Rāvaṇa, along the path the Cāraṇas travel: the open sky.
What you’ll see
Eleven chapters, ten orders of magnitude
- 01≈ 0.9 m
पाठ The recitation
The opening verse of the Sundara Kāṇḍa, chanted over a tanpura. One seated reciter, one listener 1.5 m away.
- 02≈ 1 cm
अक्षर The syllable
On the page, त is one shape. In sound it is two: the consonant t, carrying the vowel a.
- 03≈ 13 cm
स्थान Place of articulation
The five groups of stops, from the soft palate to the lips. For त the tongue tip seals against the upper teeth.
- 04≈ 13 mm
नाद The voice source
The vocal folds snap shut about 248 times a second. Each closure is a click: the raw sound of the voice.
- 05343 m/s
ध्वनि The pressure wave
The buzz leaves the lips as a wave. The mouth’s resonances, the formants, shape it into the vowel.
- 06≈ 3.3 nm
वायु Air
Molecules fly at the speed of a bullet, yet none of them carries the syllable. The wave passes through them.
- 07≈ 9 mm
श्रोत्र The ear
The eardrum rocks three tiny bones, which press the wave into the fluid of the inner ear.
- 08≈ 35 mm
शङ्ख The cochlea
Uncoiled, it sorts sound by pitch along its length: a spectrogram made of living tissue.
- 09≈ 0.3 nm
रोम A single hair cell
At the edge of hearing, its bundle tilts by about the width of an atom, and ion channels open.
- 10≈ 20 nm
नाडी A neuron fires
Glutamate crosses the gap to a nerve fibre. The vowel travels on as a pattern of spikes.
- 11≈ 10 ms
अनुकृति The repetition
A hundredth of a second after the sound leaves the lips, a pattern of spikes reaches the brain. The listener draws a breath and says it back.
In words
What the film shows, scene by scene
- 01
पाठ The reciter
The film opens on Sundara Kāṇḍa 5.1.1, chanted over a tanpura by a reciter seated on the floor, about 0.9 m tall, with a listener 1.5 m away. The pitch on screen is measured from the recording: त is sung at a fundamental frequency (f₀) of about 248 Hz, the note Pa a fifth below Sa, at roughly 2.6 syllables per second in anuṣṭubh metre.
- 02
अक्षर The syllable त
On the page, त is a shape about 1 cm across. In sound it is two things, the consonant t followed by the vowel a, because every Devanagari consonant carries a unless a virāma cancels it. The film gives it as [t̪ɐ], a voiceless, unaspirated dental stop with a short a, one mātrā long.
- 03
स्थान The mouth and the five groups
Sanskrit phoneticians mapped where each sound is made, its sthāna, and the stop consonants fall into five groups ordered from the back of the mouth to the lips: velar, palatal, retroflex, dental, labial. For त the tongue tip seals against the upper teeth and pressure of about 0.7 kPa builds behind a closure lasting about 70 ms. After the release the voice starts 23.5 ms later, and the vocal tract, about 13 cm from glottis to lips, begins to ring at its own resonances.
- 04
नाद The vocal folds
Seen from above, the folds are about 13 mm long and each swings about 1 mm. Pressure of about 0.8 kPa from the lungs pushes them open, and each time they snap shut the airflow stops abruptly: that click is the raw sound of the voice. At 248 closures a second, the clicks fuse into a pitch, about 900,000 collisions per hour of chanting.
- 05
ध्वनि The pressure wave and spectrogram
The sound leaves the lips as a wave travelling at 343 m/s with an amplitude of about 0.02 Pa at 1 m, two parts in ten million of ordinary air pressure. The wavelength of the fundamental is about 1.4 m, while the mouth’s resonances, the formants, amplify bands of the buzz and shape the vowel. The live spectrogram shows the release burst first, then the voice about 23.5 ms later.
- 06
वायु The air molecules
Zoomed in ten million times, air is mostly empty space: molecules about 3.3 nm apart, moving at about 470 m/s, faster than sound itself. Each one collides about 50 million times per cycle of the wave, and none of them carries the syllable to the listener. The sound is a shared nudge, a drift of a few tens of nanometres and back, 248 times a second.
- 07
श्रोत्र The ear
At the listener the wave is longer than the whole head, so the air in the 2.5 cm ear canal rises and falls as one. The eardrum, about 9 mm across, moves about 10 nm and rocks the hammer, anvil and stirrup. The stirrup, about 3 mm, is the body’s smallest bone, and it presses on an oval window 17 times smaller than the eardrum, a gain of about 22 times in pressure.
- 08
शङ्ख The cochlea unrolling
The cochlea is a fluid-filled tube of 2¾ turns, about 35 mm long when uncoiled, with about 3,500 inner and 12,000 outer hair cells. Along it the basilar membrane is narrow and stiff at the base and wide and floppy at the apex, so each place resonates with one frequency, from about 20 kHz at the base to 20 Hz at the apex. The syllable is taken apart by pitch, which makes the cochlea a spectrogram made of living tissue.
- 09
रोम The inner hair cell
One inner hair cell, about 35 µm tall, is crowned with a staircase of stereocilia about 5 µm high. When the bundle tilts, tip links of about 150 nm pull ion channels open within about 50 µs. At the quietest sound we can hear, the tip moves about 0.3 nm, one atom’s width, and this chanted syllable moves it only a few nanometres.
- 10
नाडी The spike in the auditory nerve
The hair cell releases glutamate across a gap of about 20 nm onto a nerve fibre, and each inner hair cell feeds about 10 to 20 fibres. The fibre fires a spike of about 100 mV lasting about 1 ms, and some 30,000 fibres leave each cochlea, travelling about 2.5 cm to the brainstem at about 15 m/s. The vowel moves on as a pattern of spikes, with the fibres tuned to the syllable’s harmonics firing hardest.
- 11
अनुकृति The listener repeats
About 10 ms after the sound left the reciter’s lips, 1.5 m of air later, the first spike is on its way to the brain. The listener draws a breath and opens their mouth to say it back. Anukriti means “made after”: imitation, repetition, mouth to ear to mouth.
अनुकृति
Anukriti means “made after”: imitation, repetition. The film ends where every recitation lesson does, with the listener opening their mouth to say it back.
That is the loop Anukriti is built around. Hear the verse from a clear voice, chant it back, and see exactly which syllables drifted, so the next repetition lands closer than the last.
Say it after, every day
Guided pronunciation for the verses you chant, a japa counter, and a festival calendar, in one app.
Tanpura: “Tanpura 10” by sankalp, dedicated to the public domain (CC0). Sizes and timings on screen are typical values from the physiology and acoustics literature, and measurements of this recording.