111 Hz benefits and the ancient chamber story

What are the claimed benefits of 111 Hz?

The benefits claimed for 111 Hz come from two places. Numerology reads 111 as an angel number, a sign of new beginnings, and the tone carries that meaning as an intention to listen with. Archaeology supplies the other story: 111 Hz is often said to be the pitch at which ancient stone chambers resonate, and so a tone chosen for ritual that acts on the brain.

Harmonance's own page calls the tone New Beginnings and suggests it for the start of something. None of these descriptions comes from a test of 111 Hz. Some videos go further and promise changes in the body itself, yet no study has tested a 111 Hz tone on the body at all. What can be checked is below: where the number comes from, what the chambers really do, and what happened when researchers played tones near 111 Hz to people.

Where does the angel number 111 come from?

The idea of angel numbers is recent. Most sources trace it to the author Doreen Virtue and her 2005 book Angel Numbers, and 111 is in the book's subtitle, as the Internet Archive's catalogue records it: "the angels explain the meaning of 111, 444, and other numbers in your life".

The usual reading of 111 is upbeat. In numerology, as Dictionary.com sums it up, 111 is "said to represent opportunity, good luck, and achievement", a sign of a new beginning. Numerology reads 111 as a stronger form of 1, the number of opportunity, determination and creation.

As a tone, 111 Hz is the number read as a frequency: 111 waves of pressure a second. Hertz is a modern unit, so nobody in the tradition chose this pitch; the number came first, and the tone is a way of carrying it into listening. The 888 Hz guide follows the same idea through the highest of the angel tones, and the guide to angel numbers and their frequencies covers the whole family.

Why is 111 Hz linked with ancient stone chambers?

Because of one acoustic survey in the 1990s. An engineer, an archaeologist and a physicist took a sound generator and meters into six ancient burial chambers in Britain and Ireland, among them Newgrange in Ireland and Wayland's Smithy in England. Five date from about 3,500 BC and one from about 500 BC. Their paper of 1996 reported that the chambers

each sustained a strong resonance at a frequency between 95 and 120 Hz, despite major differences in chamber shapes and sizes

That range sits inside the adult male voice, and the authors speculated that the chambers had been used for chanting. The guitar's open A string plays at 110 Hz, close to the middle of the range, and the team's archaeologist later suggested that sound at 110 Hz might have a special effect on the brain. A range of 95 to 120 Hz turned into one number, and 111 sits a single hertz above it.

The numbers behind the chart

Study	What was measured	Frequency
Jahn, Devereux and Ibison, 1996	Six chambers in Britain and Ireland	Each one's strongest resonance between 95 and 120 Hz
Debertolis, Coimbra and Eneix, 2015	The Oracle Room, Malta	70 and 114 Hz
Till, 2017	The same chamber, measured again	41, 72 and 76 Hz; also 134, 161, 186 and 196 Hz
Cook, Pajot and Leuchter, 2008	Tones played to 30 adults	90, 100, 110, 120 and 130 Hz

Download the chart's numbers (CSV)

Later surveys did not find one special number. In the Ħal Saflieni Hypogeum in Malta, an underground complex carved out of the rock and used in the Neolithic, a team in 2015 reported a double resonance at 70 and 114 Hz in the chamber known as the Oracle Room. They had gone in expecting something else:

This is a bit different from the 110/111 Hz that was initially expected, based on previous research in other Neolithic chambers

Two years later Rupert Till of the University of Huddersfield measured the Hypogeum again, systematically, noting in his paper in Antiquity that "previous studies have lacked rigour". He found the Oracle Chamber's primary resonances at 41, 72 and 76 Hz, with others at 134, 161, 186 and 196 Hz. 111 Hz is not among them.

Do stone chambers ring at 111 Hz by design?

Probably not, and the arithmetic shows why. A room rings most strongly between two facing walls, at any pitch whose half wavelength fits the gap once, twice or more times; these axial modes are usually the strongest a room has. Sound travels about 344 metres a second in air at 20 °C, so a wave of 111 Hz is 344 ÷ 111 = 3.10 m long, and a room 1.55, 3.10 or 4.65 m across rings at 111 Hz.

Run the same sum the other way and the 1996 range of 95 to 120 Hz is a half wavelength of between 1.43 and 1.81 m, about the size of a small stone chamber, so a chamber a few metres across can hardly avoid a resonance somewhere in that band. An acoustician at the University of Southampton, Matthew Wright, made exactly this point in 2007. Counting how many resonances a space of each chamber's size should have, he concluded:

it would have been surprising if these chambers did not have resonances between 95 and 120 Hz

The evidence that the chambers were built for chanting, he wrote, "is no stronger than it is for a typical bathroom". The resonance is real, and anyone who has sung in the shower has heard one. What it does not show is that anyone chose 111 Hz, or 110.

What happened when researchers played 110 Hz to people?

No study has played 111 Hz itself to people: PubMed, the main index of medical research, lists no listening study of the tone. Two studies have played 110 Hz, the nearest tone to it, and they asked very different questions.

30 adults and five low tones, 2008

A pilot study by Cook and colleagues played tones of 90, 100, 110, 120 and 130 Hz to 30 healthy adults while recording their brain activity with EEG (Cook, Pajot and Leuchter, 2008). One tone stood out:

Activity in the left temporal region was found to be significantly lower at 110 Hz than at other frequencies.

At 110 Hz the balance of activity at the front of the brain also moved from the left side to the right. The authors read the pattern as a quieting of areas used for language and a shift that may relate to emotion, and they called it a pilot: "a wider study of these interactions should be undertaken". No such study has been published that we could find. A change in a brain recording is not a benefit in itself, the tone was 110 Hz, not 111, and the summary does not say how long or how loud each tone played.

37 adults rating twelve pure tones, 2022

In an online test at the Australian National University, 37 adults rated twelve pure tones, 110 Hz the lowest of them, for how happy, sad, calm and angry each one sounded (Kumar, Abhayapala and Samarasinghe, 2022). 110 Hz was rated the calmest of the twelve, about 8.3 out of 10, and also the saddest, about 6.1, as read from the paper's graph of the average ratings.

The volunteers judged how each tone sounded, not how they felt. The tones always came in rising order and were rated against their neighbours, so the lowest tone sat at one end of every trend. What the test does suggest is that a low pure tone is heard as calm more readily than a high one, which is worth knowing when you choose a tone to settle with.

What the two add up to

Neither study tested 111 Hz, and neither shows a benefit. One found a difference in brain recordings at 110 Hz that nobody has repeated; the other found that people hear 110 Hz as calm. The wider field is not much further along. The US National Center for Complementary and Integrative Health sums up research on music in general:

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

For listening, take 111 Hz for what it is: a low, steady tone with a long story behind its number. If you play it at the start of something, notice what it does for you, and keep that as your own experience rather than a measured effect.

What does 111 Hz sound like?

111 Hz is a low tone, in the range of a deep speaking voice. On a piano tuned to A at 440 Hz, the A two octaves lower is 110 Hz, the guitar's open A string, and 111 Hz sits 15.7 cents above it, where a cent is a hundredth of a semitone. Play the two together and you hear them beat, the sound swelling and fading once a second. Its octaves, the same note higher up, are 222, 444 and 888 Hz.

The 111 Hz page plays it in two ways, and we measured both from the page's own audio files.

The 111 Hz page, measured

Octave band	Tone alone	Strings
3,552 Hz, five octaves up	0%	0%
1,776 Hz, four octaves up	0%	0.2%
888 Hz, three octaves up	0%	3.9%
444 Hz, two octaves up	0%	23.2%
222 Hz, one octave up	0.5%	52.3%
111 Hz, the tone itself	99.5%	19.0%
55.5 Hz, one octave down	0%	1.3%

Download the measurements (CSV)

With Strings off, the page plays the tone on its own, and 99.5% of the sound sits in the band around 111 Hz. It is not a perfectly pure sine: two faint overtones sit above it, at 222 Hz, 23.1 dB quieter, and at 333 Hz, 34 dB quieter, which the site's tone carries by design.

With Strings on, most of the sound moves an octave up: 52.3% of it lies in the band around 222 Hz. The strings play a chord built on 111 Hz. Their strongest note is 167.4 Hz, a fifth above it, and their eight strongest lines are 111 Hz and its octave with the third, fifth and sixth above them, a major chord with an added sixth. The exact 111 Hz tone still plays underneath, 35.3 dB below the music.

Two listeners described the pure tone under Harmonance's 111 Hz video on YouTube:

I can feel a light in my head when I listen to this

I love listening to this while working

Those are their words, not a finding. Some people use the tone as a background for work, and some sit with it and notice how it feels.

How long should you listen to 111 Hz, and how loud?

No study sets a length for 111 Hz. Harmonance's page suggests five to fifteen minutes to begin with, seated or lying down, and you can stop whenever it no longer feels comfortable. Many people play it at the start of something: a morning, a notebook, a new piece of work.

Keep the volume low, low enough to talk over. Loud listening is the one risk that is well established. The US National Center for Complementary and Integrative Health notes that "listening to music at too high a volume can contribute to noise-induced hearing loss", and the World Health Organization's safe listening advice is that "you can safely listen to a sound level of 80dB for up to 40 hours a week", with your device's volume at no more than 60% of maximum. A low tone can seem quieter than it is, which tempts people to turn it up; the 888 Hz guide compares how loud 111 and 888 Hz sound at the same level.

How do you listen to 111 Hz on Harmonance?

Press play on the 111 Hz page. With Strings off it plays the tone alone; switch Strings on beside the player and the strings carry the same note as a chord. Nothing plays until you press play, and no account is needed.

In Harmonance Studio you can set 111 Hz beside other tones and shape your own mix. Its neighbours in the family are 222 Hz, its octave, and 444 Hz, two octaves up, and the angel number collection plays all nine. The Fresh start page lists 111 Hz too, for the beginnings its number stands for.

For the wider field, what the science of sound healing shows sets out what research on sound and music has and has not found.

Sources and limits

The meaning of the number rests on a dictionary's summary of numerology and the catalogue record of the book that named angel numbers; the book's own words for 111 could not be read. The chamber story rests on the 1996 survey, read in its published summary, an acoustician's critique, and the two surveys of the Hypogeum, read in full. The research on listeners is two studies of 110 Hz, not 111: a pilot of 30 adults that has not been repeated, and an online rating test. The measurements of the 111 Hz page are Harmonance's own, made from the page's audio files, and the listeners' words are two comments under one video.

1. Internet Archive, catalogue record of Doreen Virtue (2005), Angel Numbers, Hay House: 111 in the subtitle.
2. Dictionary.com, 111 angel number: the usual reading in numerology, and where angel numbers come from.
3. Jahn, Devereux and Ibison (1996), acoustical resonances of assorted ancient structures, in the Journal of the Acoustical Society of America: six chambers between 95 and 120 Hz.
4. Science Frontiers 102 (1995), ancient acoustical engineering: the six sites, from the team's first report.
5. Wright (2007), the acoustics of Neolithic burial chambers, a lay paper for the Acoustical Society of America: why rooms that size ring in that range.
6. Debertolis, Coimbra and Eneix (2015), archaeoacoustic analysis of the Ħal Saflieni Hypogeum in Malta, in the Journal of Anthropology and Archaeology: the Oracle Room at 70 and 114 Hz.
7. Till (2017), an archaeoacoustic study of the Ħal Saflieni Hypogeum on Malta, in Antiquity: the Hypogeum measured again.
8. Hass, an acoustics primer: the speed of sound, Indiana University: 344 metres a second at 20 °C.
9. Hass, an acoustics primer: standing waves in rooms, Indiana University: axial modes.
10. Cook, Pajot and Leuchter (2008), ancient architectural acoustic resonance patterns and regional brain activity, in Time and Mind: 30 adults and five tones.
11. Kumar, Abhayapala and Samarasinghe (2022), frequency cues for human emotions, in Acoustics: 37 adults rating twelve pure tones.
12. UNSW Music Acoustics, note names and frequencies: A at 440 Hz, and how to count cents.
13. Comments under Harmonance's 111 Hz video on YouTube, quoted without names.
14. National Center for Complementary and Integrative Health, music and health: the state of music research, and loud listening.
15. World Health Organization, safe listening: weekly limits and device volume.