852 Hz benefits: the claims and the evidence

What are the claimed benefits of 852 Hz?

The benefits claimed for 852 Hz are spiritual ones, and they come from a tradition, not from measurement. The earliest list Harmonance could find that gives each Solfeggio tone a purpose is on David Hulse's SomaEnergetics site, in a copy the Internet Archive kept in 2002. His list names 852 Hz LA, "Returning to Spiritual Order". "Awakening Intuition" belongs there to the tone below it, SOL, at 741 Hz.

Later descriptions widened the claim. Harmonance's own older 852 Hz videos call it a tone of spiritual connection and awakening, and one of them ties it to the third eye chakra; its 852 Hz page now gives it a quieter name, Inner Listening. A 2023 paper in the journal Sensors lists 852 Hz as "beneficial for spiritual self-fulfillment", but the two studies it cites for its list played music with amplified high or low notes and music tuned to 432 Hz. Neither played 852 Hz.

No instrument measures spiritual order, so these meanings have never been tested, and most cannot be. What can be checked is where the number came from, what it is in music, where else it sounds, and what happened in the two small studies that played it to people.

Where does the number 852 come from?

From the digits of verse numbers in the Bible. Healing Codes for the Biological Apocalypse, a 1999 book by Leonard Horowitz and a co-author writing as Joseph Barber, a pen name, set out six numbers it called the lost tones of the Solfeggio scale. The publisher's news release said Barber was "intuitively guided to find the pattern of six repeating codes in the Book of Numbers, Chapter 7, verses 12 through 83", decoded by "reducing the verse numbers to their single digit integers".

Numbers 7 lists the gifts twelve tribal leaders brought to the tabernacle, one leader a day for twelve days. From verse 12 to verse 83 each day takes six verses, and the wording barely changes; only the names do. The sixth verse closes each day, as verse 17 does: "this was the offering of Nahshon the son of Amminadab".

Add up the digits of each verse number until one digit is left. The sixth verses of the first three days, 17, 23 and 29, give 8, 5 and 2: 1 + 7 makes 8, 2 + 3 makes 5, and 2 + 9 makes 11, which gives 2. Read together, they make 852. The other five places in the day give 396, 417, 528, 639 and 741, and each later group of three days gives the same six numbers again.

The first three days, place by place

Place in the day	Verses on days 1 to 3	Digits read
First	12, 18, 24	396
Second	13, 19, 25	417
Third	14, 20, 26	528
Fourth	15, 21, 27	639
Fifth	16, 22, 28	741
Sixth	17, 23, 29	852

The pattern belongs to the counting, not to the words: any run of numbers counted in sixes from 12 gives it, as the guide to 528 Hz shows. The news release itself named 396 and 528 but never 852. And Horowitz, answering a critical review of the book, wrote: "We ask forgiveness for our limited knowledge in the fields of music and physics."

Why is 852 Hz called LA?

Because it came sixth. The book matched its six numbers to the six syllables of a medieval singing scale, UT, RE, MI, FA, SOL and LA, taken from Ut queant laxis, a Latin hymn to Saint John the Baptist. Each of the hymn's first six half lines begins on the next note up, and each syllable is the start of one. The Catholic Encyclopedia prints the line that gives SOL and LA with those syllables in capitals: "SOLve polluti LAbii reatum". LA is the start of labii, lips, and the closing lines ask the saint to "clean the guilt from our stained lips, O Saint John".

In the hymn's melody, the half lines start on "the first six notes of the diatonic scale of C", so its LA is an A. Even then, a syllable named a step in a pattern of six notes, not one fixed pitch. As Grove's Dictionary of Music and Musicians puts it, "the same syllable is not always found in conjunction with the same letter".

And 852 Hz is not an A. In today's standard tuning, set as ISO 16 with A at 440 Hz, the nearest A is A5, at 880 Hz. 852 Hz sits 56 cents below it and 44 cents above G sharp, at 830.61 Hz, so it falls between the two notes, a little nearer G sharp. A cent is a hundredth of a semitone.

Is 852 Hz the third eye chakra frequency?

Only in modern charts. In Hindu yogic traditions the brow or third eye chakra, Ajna, is the sixth of the primary chakras, placed in the centre of the forehead between the eyebrows and pictured as a lotus of two petals. It is called the eye of intuition and intellect, and its seed syllable, ksham or the better known Om, is a sound to say aloud, not a pitch in hertz.

The pairing with 852 Hz follows the order of the numbers. Set the seven chakras beside the Solfeggio tones from 396 to 963 Hz, lowest to highest, and 852 Hz falls on the sixth, the brow, just as 963 Hz falls on the crown. As the guide to chakras and frequencies puts it, the frequencies paired with each centre in modern guides are a recent addition.

Where else do you hear 852 Hz?

On a telephone keypad. Touch-tone dialling, known in the UK as MF4, sends two tones at once for each key. In the words of the international standard, ITU-T Recommendation Q.23, "the dialling signal is composed of two frequencies emitted simultaneously when a button is pressed". Its four low tones are 697, 770, 852 and 941 Hz, one for each row of keys, and 852 Hz belongs to the row of 7, 8 and 9.

So each time you press 7, 8 or 9, you hear 852 Hz for a moment, mixed with a higher tone from the key's column. The standard lets each tone stray by up to 1.8%, so a phone sending anything from about 837 to 867 Hz still dials. Push-button phones using these tones reached the public in 1963 under the name Touch-Tone, decades before the Solfeggio numbers appeared, so the match is a coincidence.

852 Hz on a touch-tone keypad

Key	Low tone, from the row	High tone, from the column
7	852 Hz	1209 Hz
8	852 Hz	1336 Hz
9	852 Hz	1477 Hz
C, on keypads with a fourth column	852 Hz	1633 Hz

What happened when researchers played 852 Hz to people?

Two small studies have played 852 Hz on its own as a pure tone, and both point away from calm. Neither tested a spiritual effect, and neither can say what the tone does for someone listening at home. A 2026 review in the journal Cureus, written with the tones in mind, concedes for 639, 741 and 852 Hz that "there is currently little direct empirical evidence supporting these individual frequencies", in the words of Whitney and colleagues.

37 adults rating twelve pure tones, Canberra

Researchers at the Australian National University ran an online test in which 37 adults, aged 20 to 55, heard twelve pure tones for 20 seconds each: the nine Solfeggio tones plus 110, 220 and 440 Hz (Kumar, Abhayapala and Samarasinghe, 2022). For each tone they rated, from 1 to 10, how happy, sad, calm and angry it sounded, comparing it with the tone before and the tone after.

Above 440 Hz the ratings for calm, happy and sad fell as the pitch rose, and the rating for anger climbed. 852 Hz, the second highest tone, scored about 2 out of 10 for calm, level with 741 Hz and above only 963 Hz, and about 8.5 for anger, second only to 963 Hz, as read from the paper's graph of the average ratings.

The test asked how each tone sounded, not how the listeners felt. The tones always came in rising order and were judged against their neighbours, so the highest tones were bound to sit at the end of every trend. The volunteers used their own headphones at home, and the authors note that most were young and had experience of listening to audio critically.

18 adults and their skin, North Carolina

The second study, by Presley, Stamps and Davis Alexander at Winston Salem State University, measured the body while the tones played. It appeared as a brief report in the Journal of Scientific Exploration in 2026. In short:

• Who listened: 18 healthy volunteers aged 17 to 75, nine female and nine male. Most of them, 80%, had not heard of Solfeggio frequencies before.
• What they heard: six Solfeggio tones played as pure tones, 396, 417, 528, 639, 741 and 852 Hz, for five minutes each, then all six together, from a playlist by Emiliano Bruguera.
• How: through a wireless speaker 6 inches, about 15 cm, from each listener, at 75 to 79 dB, with 30 seconds of quiet between the tones.
• In what order: always the same, rising from 396 Hz, so 852 Hz was always the last single tone, about half an hour into the session.
• What was measured: the skin's conductance on two fingertips, which rises as sweat glands grow more active, a common sign of arousal.
• What changed: against the quiet before the first tone, readings rose significantly for 741 Hz, for 852 Hz, for all six together and for the quiet after the last tone. 396, 417, 528 and 639 Hz made no significant difference.
• How people felt: 12 called themselves neutral or content before and 11 after. 6 felt joy before and 2 after. Nobody felt annoyed, tired or less calm before, and 5 did after.

The authors read the result plainly: "We recognize that the results reveal an increased skin conductivity with higher frequencies, suggesting greater autonomic arousal." Arousal here means the body growing more alert, not calmer.

The order matters, though. The readings climbed steadily from one tone to the next and stayed high in the quiet after the last one, when nothing was playing. That pattern could come from half an hour of sitting still, wired to a sensor, as easily as from the tones themselves. The authors name the test that would tell the two apart: "Next steps include randomizing frequencies to account for sequential increases versus exposure." Until a study plays the tones in a random order, nobody can say what 852 Hz itself did.

What the two add up to

Neither study shows a benefit of 852 Hz, or any harm. They asked different questions of different people, one about how a tone sounds and one about what the skin does, and both found the higher tones further from calm than the lower ones. Both also played the tones in rising order, which puts 852 Hz near the end of every trend, so the two results share a weakness as well as a direction.

The other papers that mention 852 Hz did not test it. A 2023 study of zebrafish played what its authors call "solfeggio-frequency music", but its abstract names no frequency. The Sensors paper's line on spiritual self-fulfilment rests on studies of other sounds. Research on music in general goes further, but it is about music, not single tones, and NCCIH, the United States' centre for complementary and integrative health, says that "because much of the research on music-based interventions is preliminary, few definite conclusions about their effects have been reached".

For listening, the useful part is the direction. If you reach for 852 Hz to wind down, notice whether it leaves you settled or more alert. If it is the second, try a lower tone such as 174 Hz, which the Canberra volunteers rated among the calmest sounding of the twelve.

Is 852 Hz dangerous?

No, not at a comfortable volume. For hearing, what matters is how loud a sound is and for how long, and safe listening guidance is written in those terms. The World Health Organization says "you can safely listen to a sound level of 80dB for up to 40 hours a week", and advises keeping a device's volume at no more than 60% of its maximum. The US National Institute on Deafness and Other Communication Disorders is plainer still: "Sounds at or below 70 A-weighted decibels (dBA), even after long exposure, are unlikely to cause hearing loss."

Comfort is another matter. In the skin conductance study, five of the 18 listeners felt annoyed, tired or less calm by the end, after 35 minutes of steady tones at 75 to 79 dB, and in the Canberra test the high tones sounded the least calm. A steady high tone does not suit everyone. If it grates, turn it down, switch Strings on, or stop.

What does the 852 Hz page play?

Two different sounds, and Harmonance measured both from the page's own audio files, the same files the site serves. With Strings off, the page plays 852 Hz with two faint overtones, its second and third harmonics at 1704 and 2556 Hz, 23.1 and 34.0 dB quieter than the tone. They are there by design: the file's recipe adds them at 7% and 2% of the main tone's strength, so even the plain tone is not a single sine wave.

With Strings on, the strings carry the sound. They play a slow run of chords in a key whose home note is 53.25 Hz, exactly four octaves below 852 Hz, and every note they play is pitched between 53.25 and 179 Hz, two and a quarter to four octaves below the tone. With the overtones of those notes, 81% of the strings' power lies below 400 Hz and half of it below 268 Hz. The 852 Hz tone itself runs underneath, 36.9 dB below the strings as a whole, about a seventieth of their strength; on the chart, which sets it against their strongest band, it sits 28.5 dB down. To hear 852 Hz itself, keep Strings off; for a lower, fuller sound built on it, switch Strings on.

The numbers behind the chart

Strings	What was measured	Result
Off	The 1704 Hz overtone	23.1 dB below 852 Hz
Off	The 2556 Hz overtone	34.0 dB below 852 Hz
On	Share of the strings' power below 400 Hz	81%
On	Half of the strings' power lies below	268 Hz
On	Nine tenths of the strings' power lies below	428 Hz
On	The 852 Hz tone against the strings as a whole	36.9 dB quieter

Download the measured spectra (CSV)

How do you listen to 852 Hz?

Press play on the 852 Hz page at a low volume and let it run for a few minutes. Nothing plays until you press play, and no account is needed. With Strings off it is one steady tone, so any speakers or headphones will do; unlike binaural beats, it needs no different tone in each ear.

852 Hz is high for most voices. To hum with it, take one of its lower octaves instead: 426 Hz suits a higher voice and 213 Hz a lower one, and either stays in tune with it. Let each out-breath run long, and stop whenever you like.

The page for wanting to reflect sets 852 Hz beside two other tones people reach for in a quiet moment. Harmonance Studio lets you layer it with its neighbours in the Solfeggio set, 741 Hz and 963 Hz, and the Solfeggio collection holds the whole family. The guides to 963 Hz, 528 Hz and 174, 417 and 741 Hz follow the same numbers, and the introduction to the Solfeggio frequencies sets out the whole scale.

Sources and limits

The history comes from the archived pages of the people who made the claims, the music from standard references, and the keypad from the telephone standard itself. The research is two small studies: an online rating test of twelve pure tones, and a study of skin conductance in 18 people. Both played the tones in the same rising order, and neither can say what 852 Hz does for anyone. The Canberra figures are read from the paper's graph, not from a table. The measurements of the 852 Hz page are Harmonance's own, made from the page's audio files. No study has tested the spiritual meanings given to 852 Hz.

1. David Hulse, SomaEnergetics, the Solfeggio scale frequencies (Internet Archive copy, 2002): the earliest list of meanings found, with 852 Hz as LA, "Returning to Spiritual Order".
2. Tetrahedron Publishing, news release for the 1999 book (Internet Archive copy): the Numbers 7 method.
3. A review of the book and Leonard Horowitz's reply (Internet Archive copy): the pen name and the author on the book's limits.
4. Numbers 7, King James Version, eBible.org: twelve days of gifts, six verses each.
5. Hugh Henry, Ut queant laxis, The Catholic Encyclopedia (1912): the hymn's syllables and its first six notes.
6. Ut queant laxis, Wikipedia: the hymn and its translation.
7. W. S. Rockstro, Hexachord, Grove's Dictionary of Music and Musicians (Wikisource): what a syllable named.
8. A440 pitch standard, Wikipedia: standard tuning, ISO 16.
9. Ajna, Wikipedia: the third eye chakra in yogic traditions.
10. ITU-T Recommendation Q.23, push-button telephone sets: the keypad's tones and how far they may stray.
11. Dual-tone multi-frequency signaling, Wikipedia: the keypad's rows and columns, Touch-Tone and MF4.
12. Whitney and colleagues (2026), a review in Cureus: little direct evidence for the single frequencies.
13. Kumar, Abhayapala and Samarasinghe (2022), frequency cues for human emotions, Acoustics: 37 adults rating twelve pure tones.
14. Presley, Stamps and Davis Alexander (2026), Evaluating the Effects of Pure Tone Solfeggio Frequencies on Skin Conductivity, Journal of Scientific Exploration: 852 Hz and skin conductance in 18 people.
15. Modran and colleagues (2023), Sensors: the line on spiritual self-fulfilment and the studies behind it.
16. Dos Santos and colleagues (2023), zebrafish and Solfeggio-frequency music, PubMed abstract: no frequency named.
17. NCCIH, Music and health: what research on music does and does not show.
18. World Health Organization, safe listening: level and time, not pitch.
19. NIDCD, noise-induced hearing loss: the level below which long listening is unlikely to harm hearing.