Grounding Hz: the tones called grounding, and where each comes from

What frequency is grounding?

None has been shown to ground anyone. "Grounding" is a name that has settled on a handful of numbers, and each comes from a different place: two from a modern list of Solfeggio tones, one from the length of a day, one from lightning in the atmosphere and one from a planet's orbit. For a sixth, 228 Hz, Harmonance found no source at all. Knowing where a number comes from tells you what it can and cannot be.

Grounding tones and where they come from

Tone	Where the number comes from
7.83 Hz	The Schumann resonance: an electromagnetic resonance of the space between the ground and the ionosphere, not a sound
147.85 Hz	Saturn's orbit of just under 30 years, raised 37 octaves
174 Hz	The lowest of the nine Solfeggio numbers, added after the first six
194.18 Hz	One Earth day, noon to noon, raised 24 octaves
228 Hz	No source found
396 Hz	The first of the six Solfeggio numbers published in 1999

The Want to feel grounded page plays three of them, one at a time: 174 Hz, 396 Hz and Saturn's 147.85 Hz. The sections below take each number in turn, then measure what happens when two of them play together, which is where the choice of tones really shows.

Where does 194.18 Hz come from?

From the length of a day. Hans Cousto, whose tables give a tone for each planet, took the solar day, the 86,400 seconds from one noon to the next, as one very slow vibration and doubled its frequency until it could be heard. One cycle a day is 0.0000116 Hz. Doubled 24 times, it becomes 16,777,216 divided by 86,400, which is 194.18 Hz (Cousto's tuning tables; NASA's Earth fact sheet gives the same 24 hours).

It was the first frequency Cousto worked out with his method, which he called the cosmic octave, and the arithmetic is exact: 2 to the 17th power over 3 cubed times 5 squared, or 131,072 divided by 675 (Planetware's page on the Earth day tone, in German). That page gives the tone the root chakra, Muladhar, and the colour red orange. It does not call the tone calming. Its words for the effect are "Dynamisierend, energieaufbauend": dynamising, energy building. Music tuned to it, the page says, is enlivening and activating.

The link to the root chakra is a pairing by practice. Planetware's own chakra set gives the day tone to the root chakra, the year tone to the heart and the tone of the Platonic year to the crown, and says the pairings rest on "langjähriger praktischer Erfahrung", long practical experience (Planetware, chakras and tones). No study has tested it. The Earth frequency guide works through the arithmetic in full.

Why are 174 Hz and 396 Hz called grounding?

Mostly by association with the root chakra, and that association is recent. 396 Hz is the first of six numbers announced in 1999 as the "missing tones of the ancient Solfeggio scale" (the book's press release). The earliest list of meanings Harmonance has found, from 2002, gives it "Liberating Guilt and Fear" and names no chakra at all (SomaEnergetics, 2002). Harmonance found no source for the root chakra pairing that many sites now give it.

174 Hz was not one of the six. By 2007 the set had grown to nine, with 174 listed after 963 (a 2007 trademark application), and it is now the lowest of them. Harmonance found no source for its comfort and grounding labels either; the 174 Hz guide follows the number back, and the 396 Hz guide does the same for 396.

The chakra tradition itself gives no pitch. The root chakra, Muladhara, is pictured as a lotus of four petals in pink or red, with the earth element drawn as a yellow square (Muladhara). Every number now attached to it was attached by modern writers: 194.18 Hz by Cousto, 174 Hz and 396 Hz by the Solfeggio lists. The guide to chakras and frequencies sets the systems side by side.

One listening test found low tones rated calmer than high ones. When 37 adults rated twelve pure tones for how calm each sounded, the lower the tone, the calmer its rating: 174 Hz scored 8.1 out of 10 and 396 Hz 5.0 (Kumar, Abhayapala and Samarasinghe, 2022). The tones were heard in rising order, so the test cannot separate pitch from order, and it measured how a tone sounded, not whether anyone felt grounded. 194.18 Hz and 228 Hz were not among the twelve.

Is 7.83 Hz the Earth's frequency?

It is the Earth's electromagnetic resonance, and it is not a sound. Lightning powers a resonance of the space between the ground and the ionosphere, at a few low frequencies whose average measured values are about 7.8, 14.3, 20.8, 27.3 and 33.8 Hz (Simões, Pfaff and Freudenreich, NASA, 2012). These are electromagnetic waves, not vibrations of the air, so there is nothing to hear.

So a recording labelled 7.83 Hz cannot play the resonance itself; at most it carries the number as a slow pulse, or as a beat between two tones you can hear. The Schumann resonance guide sets out what is known about the resonance and about the claims made for it.

Where does 228 Hz come from?

Harmonance could not find out. 228 Hz turns up in grounding tracks online, including one Harmonance itself published in 2023, which labels it the root chakra's tone and plays it with 194.18 Hz and 396 Hz. Searches find track titles and shop listings, and none of them gives a source for the label.

228 is not one of the nine Solfeggio numbers in the 2007 list. It is not a planetary tone in Cousto's tables either: the only figures near it there, 228.90 and 228.92 Hz, are intervals worked out from other tones, and Cousto's root chakra tone is 194.18 Hz. The root chakra tradition gives no pitch at all. What can be measured is how 228 Hz behaves next to 194.18 Hz, only 33.82 Hz below it, and that is the subject of the next section.

Do grounding tones sound good together?

Some pairs blend smoothly and some flutter, and the difference is the ear's hearing bands. The inner ear sorts sound into overlapping bands. Two plain tones that fall inside one band interfere, and the sound swells and fades as many times a second as the tones are hertz apart. Faster than about 20 or 30 times a second, the ear can no longer follow the swells one by one (UNSW Music Acoustics). In a classic study, Plomp and Levelt found plain tones about a quarter of a critical band apart the most dissonant, and tones more than a band apart consonant.

The width of a band grows with pitch. By Glasberg and Moore's formula, 24.7 × (0.00437 f + 1), one band is 45.7 Hz wide at 194.18 Hz, 49.3 Hz at 228 Hz and 67.4 Hz at 396 Hz. 194.18 Hz and 228 Hz are 33.82 Hz apart, less than one band, so the 2023 mix's two lower tones rub against each other. 228 Hz and 396 Hz are 168 Hz apart, nearly three bands, and blend without beating.

Harmonance measured how strong that flutter is. Each pair was mixed sample for sample from the site's own tone files, each a pure tone at the same level, and passed through a standard model of one hearing band: the fourth order gammatone filter of Patterson's model of the ear, as Slaney sets it out. The site has no 228 Hz file, so 228 Hz was made as a pure tone at the same level. The depth says how far the band's output dips between swells: 0 is perfectly steady, 100 per cent would fall silent each time.

The numbers behind the chart

Pair	Bands apart	Flutter
174 Hz and 194.18 Hz	0.45, inside one band	71%, 20.2 times a second
194.18 Hz and 228 Hz	0.71, inside one band	48%, 33.8 times a second
228 Hz and 396 Hz	2.9	2.5%, steady
174 Hz and 396 Hz	4.1	1.1%, steady

Download the measurements (CSV)

Two of the grounded page's tones, 174 Hz and 396 Hz, make the smoothest pair of all: 4.1 bands apart, with a flutter of about 1 per cent. The page's third tone, Saturn's 147.85 Hz, is best kept apart from 174 Hz, and the page plays each tone alone: measured the same way, 147.85 Hz and 174 Hz sit 0.62 of a band apart and flutter 55 per cent deep, 26.2 times a second. Saturn's tone comes from its orbit, as the Saturn frequency guide explains, not from any rule of harmony.

None of this says which mix grounds anyone; it says which mixes sound smooth and which flutter. If what you want is a still, settled sound, tones more than a band apart give it, and tones inside one band do not.

Does any study show a frequency can ground you?

No. No study has tested a tone, or a mix of tones, for a feeling of being grounded. The closest evidence is about music in general: across 104 randomised trials with 9,617 people, music lowered measures of stress by a small to moderate amount on average (de Witte and colleagues, 2020). The trials used music, not chosen frequencies, so they say nothing about 174, 194.18, 228 or 396 Hz in particular.

Research on music and health as a whole is still at an early stage. The US National Center for Complementary and Integrative Health sums it up:

However, because much of the research on music-based interventions is preliminary, few definite conclusions about their effects have been reached.

How do you listen for grounding?

Sit or stand with your feet flat on the floor, play one tone at a comfortable volume, and notice the weight of your body. That is the invitation on the grounded page, and it asks nothing of the tone except a steady place to rest your attention. If you play two tones at once, choose a pair more than a band apart, such as 174 Hz with 396 Hz, for a smooth sound.

Keep the volume low. The World Health Organization's guide to safe listening says "you can safely listen to a sound level of 80dB for up to 40 hours a week", and suggests a device volume of no more than 60 per cent of maximum. The NCCIH adds that "listening to music at too high a volume can contribute to noise-induced hearing loss".

How do you play grounding tones on Harmonance?

Press play at the top of this guide to hear 174 Hz, or open the Want to feel grounded page for all three of its tones. Each has its own page too: 174 Hz, 396 Hz, Saturn at 147.85 Hz and the Earth day at 194.18 Hz. Nothing plays until you press play, and no account is needed.

To hear two tones together, open Harmonance Studio, the free Harmonance instrument, which plays several tones at once after you sign in with a free account. Try 174 Hz with 396 Hz, then swap 396 Hz for 194.18 Hz and listen for the flutter. The grounding theme gathers the tones Harmonance files under grounding.

Sources and limits

No tone has been shown to ground anyone. The origins of 194.18 Hz and 147.85 Hz are arithmetic anyone can redo; Harmonance found no source for the grounding meanings of 174 Hz and 396 Hz, nor for 228 Hz itself. The calm ratings come from one small test: 37 young adults on their own headphones, hearing the tones in rising order. The flutter measurements are Harmonance's own, made from the files the pages play, through a standard model of one hearing band; a real ear differs from the model, and from one person to the next.

1. Hans Cousto, tuning data for the planets, Planetware: the Earth day and Saturn tones.
2. Hans Cousto, the Earth day tone, Planetware, in German: the arithmetic, the root chakra and its effect.
3. Planetware, chakras and tones, in German: the planetary chakra set and what it rests on.
4. NASA, Earth fact sheet: the length of a day.
5. Simões, Pfaff and Freudenreich (2012), Schumann resonances in the Earth's ionosphere, NASA Goddard: what 7.83 Hz is.
6. Tetrahedron Publishing (1999), press release for Healing Codes for the Biological Apocalypse, Internet Archive: the first six Solfeggio numbers.
7. SomaEnergetics (2002), the Solfeggio scale frequencies, Internet Archive: the earliest list of meanings.
8. United States Patent and Trademark Office, trademark application 77099679: the nine numbers by 2007.
9. Muladhara, Wikipedia: the root chakra in the tradition.
10. Kumar, Abhayapala and Samarasinghe (2022), a preliminary investigation on frequency dependant cues for human emotions, in Acoustics: 37 listeners rate twelve pure tones.
11. UNSW Music Acoustics, interference beats: how fast two close tones beat.
12. Plomp and Levelt (1965), tonal consonance and critical bandwidth, in The Journal of the Acoustical Society of America: when two tones sound smooth or rough.
13. Moore (2014), the Cambridge loudness models, in Trends in Hearing: the width of the ear's bands.
14. Slaney (1993), an efficient implementation of the Patterson and Holdsworth auditory filter bank: the model of one hearing band.
15. de Witte and colleagues (2020), music interventions and stress, two meta-analyses, in Health Psychology Review: 104 randomised trials.
16. National Center for Complementary and Integrative Health, music and health: the state of the research, and loud listening.
17. World Health Organization, safe listening: how loud, and for how long.