417 Hz benefits: where the claims come from

417 Hz is the second of the six Solfeggio numbers printed in 1999, paired with RE, a syllable from a medieval hymn. Its best-known benefit, undoing situations and facilitating change, is first found on a tuning fork seller's page in 2002, drawn by his account from dictionary entries. No study shows a benefit. In the one listening test found, 37 adults rated it near the middle of every scale.

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Long orange ribbons of light flowing edge to edge across a deep, dark field, bowing gently under the centre — Illustration. The Harmonance wave field in the orange of 417 Hz. The field gives each pitch its own wavelength, so these long, slow waves are drawn from 417 Hz itself.

What benefits are claimed for 417 Hz?

Nearly everything claimed for 417 Hz is about change. The best-known label says it undoes situations and facilitates change. Newer descriptions add the clearing of negative energy, and modern chakra charts match it with the sacral chakra, the second of the seven.

Harmonance's 417 Hz page calls it Change and Clearing and suggests it for the moment you start a task or shift gears. We offer that name as an intention to listen with. None of these descriptions rests on a measurement: the number was printed in 1999 with no benefit attached, the earliest record of the label for change is from 2002, and the one test found that played 417 Hz to people placed it in a range its authors call neutral.

Where does 417 Hz come from?

The number comes from a 1999 book, Healing Codes for the Biological Apocalypse, which drew six frequencies out of the Bible's Book of Numbers. Its publisher's press release describes the method as "reducing the verse numbers to their single digit integers": add the digits of a verse number together, and keep adding until one digit is left.

Chapter 7 of Numbers lists the gifts that twelve princes of Israel brought on twelve days, one prince a day and six verses to each day. On every day the second verse begins the list of gifts with "one silver charger": verse 13 on the first day, 19 on the second and 25 on the third. The digits of 13 add up to 4. Those of 19 add up to 10, and 1 and 0 make 1. Those of 25 add up to 7. Read in order, the three make 417, and over the twelve days the same three digits come round four times. The guide to the Solfeggio frequencies runs the same rule for all nine numbers.

The press release gives the second tone a syllable and no benefit. Of RE it says only that the syllable is short for "resonare fibris" or resonance, and that it "also correlates mathematically to 144,000", a number from the Book of Revelation.

Resonare fibris is half a line of Ut queant laxis, a Latin hymn to John the Baptist. Its first verse gave music the old syllables UT, RE, MI, FA, SOL and LA, each taken from the start of a half line, and in English it runs: "So that they may, with loosened voices, resound the wonders of your deeds, clean the guilt from our stained lips, O Saint John." RE's half line holds the words about resounding. The words about cleansing begin with SOL.

In 1999, then, 417 came with a syllable and a sum, and with no promise of change. The meaning arrived later, one step at a time.

Four steps on an orange line: the hymn's resonare fibris, 417 in 1999, Undoing Situations and Facilitating Change in 2002, change and clearing today — The meaning of 417 Hz arrived in steps: a syllable from a medieval hymn, a number from verse numbers in 1999, a label for change from a tuning fork seller in 2002, and the name Harmonance's page uses today.

Who first said 417 Hz facilitates change?

The earliest record found is a page from SomaEnergetics, David Hulse's company, which sold Solfeggio tuning forks. As the Internet Archive saved it in December 2002, the page gives each of the six tones a label, and for RE at 417 Hz the label is "Undoing Situations and Facilitating Change". The page does not say where the label came from.

By 2006 the company's site explained the method. Hulse wrote that he had worked from "the definitions of each of the original syllables", using what he called "hidden entries" in Webster's Dictionary and the Greek Apocrypha, and among the uses he drew from them was "solving situations & becoming more intuitive". He does not say which entries he used.

A dictionary was already part of the story in 1999. The press release defined UT from Webster's Dictionary as "the Gamut of dramatic emotion from grief to joy", and the 2006 list of uses begins "Turning grief to joy". No such entry is quoted for RE in any of these pages, so how words about resounding became a label about undoing situations is not explained.

Nor do the labels follow the hymn. Its words about cleansing, and the guilt they wash away, sit in the half lines of SOL and LA, yet the 2002 page gives SOL, at 741 Hz, the label "Awakening Intuition", and gives guilt to UT, at 396 Hz, as "Liberating Guilt and Fear". Today the clearing belongs to RE, whose half line is about resounding.

Is 417 Hz the sacral chakra frequency?

It is in modern charts, but the match is recent. In Hindu Tantra the sacral chakra, Svadhishthana, is the second of the primary chakras, drawn as a lotus whose petals are inscribed with syllables. The old descriptions give it petals, syllables and an element. They give it no pitch.

The match follows the order of the set. The common chart climbs the Solfeggio numbers from 396 Hz at the root to 963 Hz at the crown, so the second number lands on the second centre. The guide to chakras and frequencies sets out the whole chart, and notes that the frequencies are a recent addition to it.

What happened when researchers played 417 Hz to people?

Only one study could be found that played 417 Hz to listeners and reported what they made of it. Researchers at the Australian National University in Canberra ran it online, and 37 adults with normal hearing took part, aged 20 to 55, with a median age of 27 (Kumar, Abhayapala and Samarasinghe, 2022). Each volunteer heard twelve pure tones on their own headphones: the nine Solfeggio tones, with 110, 220 and 440 Hz added. Every tone played for 20 seconds, always in rising order, and the volunteers gave it four scores out of 10, for how happy, sad, calm and angry it sounded beside the tones before and after it.

The authors' main finding is about the middle of the run. They report that the crossover points of all four ratings lie between 417 and 440 Hz, and they call that range neutral. On the paper's graph of average ratings, calm falls and anger climbs as the pitch rises, and the lines meet in the middle.

Line chart of average ratings out of 10 for twelve tones: calm falls and anger rises with pitch, and at 417 Hz all four sit between 4.5 and 4.8 — Average ratings out of 10 from the 37 Canberra volunteers, read from the paper's graph: as the pitch rises, calm falls and anger climbs, and at 417 Hz the four ratings sit between 4.5 and 4.8, closer together than at any other tone.

Each tone's lowest and highest rating
Tone	Lowest to highest rating	Gap
110 Hz	3.1 to 8.3	5.2
174 Hz	2.6 to 8.1	5.5
220 Hz	2.7 to 7.6	4.9
285 Hz	3.1 to 6.7	3.6
396 Hz	4.4 to 5.0	0.6
417 Hz	4.5 to 4.8	0.3
440 Hz	4.3 to 5.0	0.7
528 Hz	3.3 to 6.2	2.9
639 Hz	2.5 to 7.4	4.9
741 Hz	2.2 to 8.1	5.9
852 Hz	2.2 to 8.6	6.4
963 Hz	1.9 to 9.1	7.2

Download the ratings (CSV)

The paper gives its averages only as a graph, and its data only on request, so the numbers here are our reading of that graph, point by point. Read that way, 417 Hz is where the four ratings sit closest together: 0.3 apart, against 0.6 at 396 Hz, 0.7 at 440 Hz, 5.5 at 174 Hz and 7.2 at 963 Hz. At 417 Hz no rating stands out from the others.

Two things limit what this can show. The tones always came in the same rising order and were judged against their neighbours, and 417 Hz was sixth of the twelve, in the middle of the run, which may by itself pull its scores towards the middle of each scale. And the test measured how a tone heard for 20 seconds sounded to listeners at home, not what it did for them. The authors name their own limits too: an online test, varied equipment, and a sample "dominated by a young age group".

So choosing 417 Hz means choosing a tone these volunteers, on average, placed in the middle of all four scales. If calm is what you are after, they gave 174 Hz about 8 out of 10 for calm, against under 5 for 417 Hz.

Is there any research on 417 Hz and mental health?

A 2025 review posted on Research Square, a site for papers that have not yet been through peer review, says it drew on twelve studies of 417 Hz and reports moderate effects on measures of mental health. It carries the site's own warning: "This is a preprint; it has not been peer reviewed by a journal."

The studies behind it are hard to find. Its reference list names three papers on 417 Hz by title, journal, volume and pages, none with a DOI, the permanent link most journal papers carry. A search of Crossref, which registers most of those links, finds no paper with any of the three titles, and PubMed holds none of them. The one Solfeggio review in the list that does give a DOI, 10.1016/j.chb.2021.107124, leads to a different paper: a 2022 review of gaming and the avatars players use, in Computers in Human Behavior. Anyone can repeat these checks.

No other study of listening to 417 Hz turned up. PubMed, the US National Library of Medicine's index of research, holds no such study: the few papers there that mention 417 Hz concern heart rhythms, hearing in gerbils, stimulation of the hearing nerve and children's voices. A 2026 study in the Journal of Scientific Exploration measured skin conductance in people hearing "six specific frequencies, including 528 Hz", and its summary reports that "741 Hz and 852 Hz increase skin conductivity". The summary does not name the other three tones and the full paper could not be opened, so whether 417 Hz was among them is not known.

Research on music and health as a whole is at an early stage. The US National Center for Complementary and Integrative Health notes that because much of it is preliminary, "few definite conclusions about their effects have been reached".

What does 417 Hz sound like?

417 Hz sits just above the G sharp above middle C. On a piano tuned to A at 440 Hz that key is 415.30 Hz, so 417 Hz is 7 cents above it, a cent being one hundredth of the step between neighbouring keys. Halve it and you get the same note an octave lower, so its lower octaves are 208.5, 104.25 and 52.125 Hz.

We measured both ways the 417 Hz page plays it, from the page's own audio. With Strings off, it plays the tone alone, and 99.5% of the sound's energy lies within half an octave of 417 Hz. What remains is two faint overtones at twice and three times the pitch: 834 Hz, 23.1 dB below the tone, and 1,251 Hz, 34 dB below.

With Strings on, the sound moves under the tone. The strings play a chord on G sharp, the note of 417 Hz, and all eight of its strongest pitches lie below 417 Hz. Almost two thirds of the energy, 64.2%, sits one and two octaves down, in the bands around 104.25 and 208.5 Hz, and 31.5% lies in the band around 417 Hz itself, which holds the chord's highest notes, E flat and F. The strongest single pitch is the G sharp at 209 Hz, an octave below 417 Hz. The exact 417 Hz sine still plays beneath the strings, 35.5 dB under the music.

The eight strongest pitches in the Strings sound on the 417 Hz page, lowest first: G sharp, the note of 417 Hz, in two lower octaves, with the notes a third, fourth, fifth and sixth above it.

The Strings chord, pitch by pitch
Pitch	Nearest piano key	Place in the chord
104.4 Hz	G sharp 2	the note of 417 Hz, two octaves down
139.2 Hz	C sharp 3	a fourth above G sharp
157.0 Hz	E flat 3	a fifth above G sharp
176.4 Hz	F 3	a sixth above G sharp
209.0 Hz	G sharp 3	the note of 417 Hz, one octave down
261.2 Hz	C 4	a third above G sharp
313.3 Hz	E flat 4	a fifth above G sharp
348.6 Hz	F 4	a sixth above G sharp

Download the chord (CSV)

How long should you listen to 417 Hz, and how loud?

No study gives a length for 417 Hz: the Canberra test played it for 20 seconds. Harmonance's page suggests ten to twenty minutes as you start a task or shift gears, at a volume you can still think clearly over, and you can stop whenever it stops feeling comfortable.

Keep the volume low. The Canberra volunteers were asked to set their headphones at 15 to 20% of full volume. The documented risk is loudness, not any particular tone: the US National Center for Complementary and Integrative Health warns that "listening to music at too high a volume can contribute to noise-induced hearing loss", and the World Health Organization puts the safe limit at 80 dB for up to 40 hours a week, with your device at no more than 60% of its maximum volume.

How do you listen to 417 Hz on Harmonance?

Press play at the top of this guide, or open the 417 Hz page, where the Strings switch beside the player adds the chord measured above. Nothing plays until you press play, and you need no account.

In Harmonance Studio, once signed in, you can layer 417 Hz with other tones and set a timer. Its neighbour below in the set is 396 Hz, and the Solfeggio collection holds all nine.

Two of the site's feeling pages include it: Hit a creative block? offers 417 Hz first, and Want a fresh start? lists it among its tones.

For more of the story, the 528 Hz guide and the 963 Hz guide trace two of 417 Hz's companions in the set, and 174, 417 and 741 Hz follows three tones together. The science of sound healing sets out what research on sound has and has not found.

Sources and limits

The history rests on the 1999 press release, the King James text of Numbers 7, the hymn and its translation, and two SomaEnergetics pages kept by the Internet Archive. The 1999 book itself was not read; its press release is the earliest record used here. The research is one online rating test of pure tones, whose averages are our reading of its published graph, and a preprint whose 417 Hz sources could not be traced. Neither tells you what 417 Hz does for a listener. The skin conductance study could be read only in summary, which leaves open whether it tested 417 Hz. We measured the 417 Hz page's sound ourselves, from its audio files.