- 440 Hz is the standard concert pitch for the note A above middle C, confirmed in 1975 as ISO 16; in the 432 Hz tuning the same note is 8 Hz lower.
- The distance between 432 Hz and 440 Hz is 31.77 cents, a little less than a third of a semitone, and a recording moves from one to the other with a pitch change of 1.82 %.
- In five studies with 12 to 54 participants the body was calmer with 432 Hz music than with the same music at 440 Hz or 443 Hz: in one of them the heart rate was 4.79 beats a minute lower.
- In two studies, of 28 kickboxers and of 22 male athletes, music at 440 Hz during the warm-up gave better performance than the same music at 432 Hz.
- Pitch was never standardised at 432 Hz: France fixed the note A at 435 Hz on 16 February 1859, and delegates of five countries agreed on 440 Hz in London in May 1939.
- No study has described a harm of 440 Hz or of 432 Hz; the World Health Organization considers sound of up to 80 dB safe for 40 hours a week.
432 Hz vs 440 Hz: the difference
Both numbers name the pitch of one note, the A above middle C. In standard tuning it is 440 Hz. In the 432 Hz tuning it is 8 Hz lower, and every other note moves down with it. The distance is 31.77 cents, a little less than a third of a semitone. The music is the same, note for note; it sounds slightly lower and, to many listeners, softer.
| 432 Hz tuning | 440 Hz tuning | |
|---|---|---|
| Note A4 | 432 Hz | 440 Hz |
| Note C5 | 513.74 Hz | 523.25 Hz |
| Distance from the standard | 31.77 cents lower | None, it is the standard |
| Wavelength of the note A in air | 79 centimetres | 78 centimetres |
| Who uses it | Musicians and listeners who choose it | The international standard; nearly all music you have ever heard |
| What studies found | A little more calm: lower heart rate, lower cortisol, better sleep scores | Better results in sport and movement |
Does 432 Hz sound different, and does it really sound better
It sounds different when you hear the two tunings one after the other. Heard alone, a piece in 432 Hz cannot be told from a piece in 440 Hz by most listeners, because few people have absolute pitch.
The generator lets you test this on yourself. It opens in the 432 Hz tuning with a melody, the opening four bars of the Prelude in C major by Johann Sebastian Bach, and a 5-minute timer.
- Press Play and let the four bars repeat once or twice.
- Switch the tuning to 440 Hz while the melody plays. The sound changes at once.
- Switch back to 432 Hz. Listen for the step down and for the change of colour: many listeners find the lower tuning softer.
- Notice what does not change: the notes of the melody and the distances between them. The whole piece moves together.
- Change the sound to the note A and switch again. With a single pure tone the step is easiest to hear.
Whether 432 Hz sounds better depends on the listener and on the moment. In a double-blind study of 33 volunteers the listeners were more focused on the music and more satisfied after the 432 Hz sessions. In a study of 28 kickboxers the best mood came with 440 Hz during the warm-up.
What is 440 Hz: the note, the standard tuning and its benefits
440 Hz is the note A above middle C, written A4, in standard tuning. All other notes are tuned from it: the A one octave lower is 220 Hz, the next one 110 Hz, and middle C comes out at 261.63 Hz. The standard tuning fork that musicians have used for generations gives this note.
The first benefit of 440 Hz is practical. It is a standard agreed so that instruments made in different countries can play together.
The second benefit was measured in sport. In a double-blind study 28 kickboxers, 15 men and 13 women, warmed up with their preferred music at 440 Hz and at 432 Hz and then took an intermittent anaerobic speed test. Music in both tunings improved the results compared with no music, and 440 Hz gave the best performance and the best mood. In a second study, of 22 male athletes, the benefits were again more noticeable at 440 Hz, in sprints and jumps.
432 Hz vs 440 Hz: what head-to-head studies found
Seven studies gave people the same music in two tunings. Five looked at calm, two at performance in sport. Four of them were double-blind: neither the listeners nor the people who measured them knew which tuning was playing.
| Study | Who and how | With 432 Hz | With 440 Hz or 443 Hz |
|---|---|---|---|
| Calamassi and Pomponi, 2019, Italy | 33 healthy volunteers, 20 minutes of the same film music on two different days | Heart rate lower by 4.79 beats a minute, breathing rate lower by 1 breath a minute | Higher heart rate and breathing rate |
| Calamassi and colleagues, 2020, Italy | 12 patients with spinal cord injuries, favourite music for 30 minutes a day | Sleep score +3.6 (p = 0.02) | Sleep score −1.50 (p = 0.34), no significant change |
| Calamassi and colleagues, 2022, Italy | 54 emergency healthcare workers, music in the work break | Anxiety fell; breathing rate fell by 2.7 breaths a minute, systolic blood pressure by 3.8 mmHg | Anxiety fell; breathing rate and blood pressure did not fall |
| Aravena and colleagues, 2020, Chile | 42 patients with moderate anxiety, 15 minutes of music before a tooth extraction | Anxiety score 8.7, cortisol 0.49 μg/dL | Anxiety score 8.4, cortisol 1.35 μg/dL |
| Hohneck and colleagues, 2025, Germany | 43 cancer patients, median age 61, two 15-minute sessions with a body monochord | Heart rate fell by 3 beats a minute, heart rate variability rose, pulse wave velocity fell by 0.5 m/s | 443 Hz: heart rate fell by 1 beat a minute, heart rate variability did not rise |
| Jebabli and colleagues, 2025, PeerJ | 28 kickboxers, preferred music during the warm-up | Better test results than without music | The best performance and the best mood |
| Jebabli and colleagues, 2025, Scientific Reports | 22 male athletes, preferred music during the warm-up | Better performance than without music | The more noticeable benefit, in sprints and jumps |
In the study of volunteers the difference in heart rate stood at the edge of statistical significance (p = 0.05) and the difference in breathing rate just beyond it (p = 0.06). Blood pressure was slightly lower with 432 Hz, not significantly.
The dental trial had a third group without music, with an anxiety score of 17.2 and cortisol of 1.59 μg/dL. So music in either tuning halved the anxiety, and it was the cortisol that separated 432 Hz from 440 Hz.
The emergency workers also had a third group, a break without music, and anxiety fell there too. In the patients with spinal cord injuries stress fell with both tunings, not significantly.
In the German trial the instrument was a body monochord, a string instrument placed against the body, and the higher tuning was 443 Hz. The difference in heart rate was significant (p = 0.04), and pulse wave velocity fell significantly more with 432 Hz. Well-being, anxiety and stress improved with both tunings.
Is 432 Hz really better than 440 Hz
For calm, yes, a little. The studies point the same way: music tuned to 432 Hz calms the body a little more than the same music at 440 Hz. The heart was slower, cortisol was lower, the sleep score was better.
For movement, no. In both studies of athletes 440 Hz suited sport better.
For how people feel the two are often equal. Anxiety scores fell as much with 440 Hz as with 432 Hz in the dental trial, and well-being improved with both tunings in the cancer patients. In these measures the music did the work, and the tuning added little.
The limits apply to every line above. The studies are small, 12 to 54 people, and several are pilot studies by the same Italian group. None lasted longer than a few weeks. Larger studies are needed.
Concert pitch: why the standard is 440 Hz and not 432 Hz
Concert pitch is the frequency that musicians agree to give the note A. For centuries there was no agreement. Pitch differed from town to town and from organ to organ, and surviving French tuning forks show how far it moved.
In the 19th century pitch kept rising, because higher tuning sounds more brilliant. It strained singers' voices. Largely because of their protests the French government fixed A at 435 Hz by law. This standard was called the diapason normal.
440 Hz is older than its reputation. The German physicist Johann Heinrich Scheibler recommended it in 1834, and it is also called Stuttgart pitch after the city where German natural scientists approved it.
| Year | Event | Pitch of A |
|---|---|---|
| 1795 | Organ fork of the Versailles chapel | 390 Hz |
| 1810 | Fork of the Paris Opera | 423 Hz |
| 1822 | A surviving French fork | 432 Hz |
| 1834 | Scheibler recommends a pitch, a meeting in Stuttgart approves it | 440 Hz |
| 1855 | A surviving French fork | 449 Hz |
| 1859 | French law of 16 February, the diapason normal | 435 Hz |
| 1885 | A conference in Vienna adopts the French standard for Italy, Austria, Hungary, Russia, Prussia, Saxony, Sweden and Württemberg | 435 Hz |
| 1926 | The American music industry reaches an informal standard | 440 Hz |
| 1936 | The American Standards Association recommends it | 440 Hz |
| 1939 | Meeting at Broadcasting House in London | 440 Hz |
| 1955 | The International Organization for Standardization takes it up | 440 Hz |
| 1975 | Confirmed as the standard ISO 16 | 440 Hz |
When the London meeting chose 440 Hz, the pitch had been recommended in Germany for a century and used by the American music industry for 13 years. The meeting confirmed what two large musical worlds already did.
Why 432 Hz changed to 440 Hz: it never did
The question assumes that music was once tuned to 432 Hz and later moved to 440 Hz. It was not. No standard ever set the note A at 432 Hz.
What changed in 1939 was smaller. The countries that followed the French standard moved from 435 Hz to 440 Hz. British musicians, who had used 439 Hz since the end of the 19th century, moved by 1 Hz.
432 Hz enters the story as a proposal. Giuseppe Verdi wrote his Requiem of 1874 for the French standard of 435 Hz and later said that 432 Hz would be slightly better for orchestras, which is why 432 Hz is called Verdi tuning. A campaign to make it the standard began in 1988. The main page about 432 Hz tells where the number comes from.
Did the Nazis introduce 440 Hz
The story says that 440 Hz was imposed by Goebbels. No evidence supports it.
The dates speak against it. 440 Hz was recommended in Germany in 1834 and was the informal American standard from 1926. In May 1939 it was agreed by delegates from France, Germany, the Netherlands, Italy and England; Switzerland and the United States took part by mail. They met in London, at the headquarters of the BBC.
Germany was one of five countries in the room, and the pitch they chose was the one the American industry already used.
Is 440 Hz bad for you
No harm has been shown. No study has described a harm of 440 Hz, and nearly all music you have ever heard is tuned to about 440 Hz.
In the studies on this page 440 Hz music was the comparison, and it helped too: it halved the anxiety before a tooth extraction and improved the results of athletes.
Hearing is harmed by loudness and duration, not by a particular frequency. The World Health Organization considers sound of up to 80 dB safe for 40 hours a week, in any tuning.
432 Hz vs 440 Hz: the spiritual meaning
Supporters call 432 Hz the natural tuning. The tradition links it with calm, with the Earth and with the universe, and speaks of 432 Hz music as healing. To 440 Hz the same tradition gives the opposite role: a standard that was imposed.
The spiritual meaning of 432 Hz rests on numbers: the resonance of the Earth rounded to 8 Hz and multiplied by 54, middle C set to 256 Hz, the golden ratio. These are number patterns, and they say nothing about the sound. The main page about 432 Hz goes through them one by one.
It is not shown that 432 Hz is the frequency of the Earth or of the universe, or that 440 Hz harms anyone. What is shown is smaller and real: in several studies people were calmer in body with the lower tuning. If 432 Hz music helps you to become quiet, that experience has some ground.
432 Hz vs 444 Hz and other pitches: 415, 435 and 443 Hz
The standard is an agreement, and orchestras do not all keep to it. Six other values of the note A are in use or have a place in history.
| Pitch of A | Compared with 440 Hz | Where it is used or comes from |
|---|---|---|
| 415 Hz | 25 Hz lower | Ensembles that play baroque music on period instruments |
| 432 Hz | 8 Hz lower | Verdi tuning |
| 435 Hz | 5 Hz lower | The French standard of 1859 |
| 439 Hz | 1 Hz lower | British musicians from the end of the 19th century |
| 443 Hz | 3 Hz higher | Professional orchestras in Germany |
| 444 Hz | 4 Hz higher | The tuning in which the note C5 is 528 Hz |
432 Hz vs 444 Hz: with A = 444 Hz the note C5 is 528 Hz, which is why 444 Hz tuning is linked with the solfeggio tone 528 Hz. In the 432 Hz tuning the note C5 is 513.74 Hz. The page about 432 Hz vs 528 Hz compares the two.
432 Hz or 440 Hz: which to choose and when
You do not have to take a side. Use each tuning where the studies found its strength.
| Situation | Tuning | Why |
|---|---|---|
| Evening, rest, winding down | 432 Hz | Lower heart rate and breathing rate in the studies |
| Before sleep | 432 Hz | The sleep score improved with 432 Hz and not with 440 Hz |
| Before a dental or medical procedure | Either, with a small advantage for 432 Hz | Anxiety fell equally; cortisol was lower with 432 Hz |
| Training, warm-up, a task that needs energy | 440 Hz | The best performance and mood in athletes |
| Playing with other musicians | 440 Hz, or the pitch the group agrees on | All instruments need the same reference |
The evening use is described step by step on the pages about 432 Hz for sleep and 432 Hz meditation.
How to use the generator on this page
Everything you hear is made in the browser at the moment you press Play. These are the controls.
- Tuning: A = 432 Hz or A = 440 Hz. The switch works while the sound plays.
- Sound: the melody, the note A as a pure tone, or a chord of the notes A, E and A in a low register that swells and fades once every 12 seconds.
- Display: the frequency of A4 and C5 in the chosen tuning and the distance from the standard, 31.8 cents lower.
- Binaural beat, for the note and the chord: 2 Hz (delta), 6 Hz (theta) or 10 Hz (alpha). The left ear hears the tone and the right ear the tone plus the beat, so use headphones. The melody plays without a beat.
- Background: quiet brown noise, on or off.
- Volume and timer: 5, 15, 30 or 60 minutes, with a gradual fade-out. This page starts with 5 minutes.
In the studies people listened to music, not to a pure tone. The note and the chord are a way to hear the tuning; for the effects that were measured, quiet music is the closer match.
With a binaural beat do not listen while driving, and if you have epilepsy talk to your doctor first.
Questions people ask
What is the difference between 432 Hz and 440 Hz?
Both are pitches of the note A above middle C. 440 Hz is the standard; 432 Hz is 8 Hz or 31.77 cents lower, a little less than a third of a semitone. All other notes move with it, so the same music sounds slightly lower.
Is 432 Hz better than 440 Hz?
For calm, a little: in small studies heart rate, cortisol and sleep scores were better with 432 Hz music. For sport 440 Hz did better in two studies. Larger studies are needed.
Does 432 Hz sound different from 440 Hz?
Yes, when the two are played one after the other: 432 Hz sounds slightly lower and, to many listeners, softer. Heard alone, most people cannot tell which tuning a piece is in.
Why was 432 Hz changed to 440 Hz?
It was not. 432 Hz was never a standard. The French standard of 1859 was 435 Hz, British musicians used 439 Hz, and in May 1939 delegates of five countries agreed on 440 Hz in London.
Is 440 Hz bad for you?
No harm has been shown. Nearly all music you have ever heard is tuned to about 440 Hz. Hearing is harmed by loudness and duration, not by a particular frequency.
What note is 440 Hz?
The note A above middle C, written A4. It is the reference of standard tuning: the A one octave lower is 220 Hz, and middle C is 261.63 Hz.
What are the benefits of the 440 Hz frequency?
It is the standard that lets instruments made in different countries play together. In two studies of athletes music at 440 Hz during the warm-up gave better performance than the same music at 432 Hz.
What is concert pitch?
The frequency that musicians agree to give the note A. The international standard is 440 Hz, confirmed in 1975 as ISO 16. Professional orchestras in Germany tune to 443 Hz, and baroque ensembles often use 415 Hz.
Did the Nazis introduce the 440 Hz tuning?
No evidence supports it. 440 Hz was recommended in Germany in 1834, was the informal American standard from 1926 and was agreed in London in 1939 by delegates of five countries.
What is the difference between 432 Hz and 444 Hz?
Both are tunings of the note A. With A = 444 Hz the note C5 is 528 Hz, the solfeggio tone, which is why that tuning is linked with 528 Hz. With A = 432 Hz the note C5 is 513.74 Hz.
- Calamassi D., Pomponi G. P. Music tuned to 440 Hz versus 432 Hz and the health effects: a double-blind cross-over pilot study. Explore, 2019, 15 (4), 283–290.
- Calamassi D., Lucicesare A., Pomponi G. P., Bambi S. Music tuned to 432 Hz versus music tuned to 440 Hz for improving sleep in patients with spinal cord injuries: a double-blind cross-over pilot study. Acta Biomedica, 2020, 91 (12-S), e2020008.
- Calamassi D. et al. The listening to music tuned to 440 Hz versus 432 Hz to reduce anxiety and stress in emergency nurses during the COVID-19 pandemic: a double-blind, randomized controlled pilot study. Acta Biomedica, 2022, 93 (S2), e2022149.
- Aravena P. C., Almonacid C., Mancilla M. I. Effect of music at 432 Hz and 440 Hz on dental anxiety and salivary cortisol levels in patients undergoing tooth extraction: a randomized clinical trial. Journal of Applied Oral Science, 2020, 28, e20190601.
- Hohneck A. et al. Differential effects of sound interventions tuned to 432 Hz or 443 Hz on cardiovascular parameters in cancer patients: a randomized cross-over trial. BMC Complementary Medicine and Therapies, 2025, 25, 18.
- Jebabli N. et al. Effects of 440-Hz vs. 432-Hz preferred music frequencies, during warm-up, on intermittent anaerobic speed test performance in men and women kickboxers: a double-blind crossover study. PeerJ, 2025, 13, e19084.
- Jebabli N. et al. Effect of listening to preferred music at different frequencies during warmup on physical performance and psychophysiological responses in male athletes. Scientific Reports, 2025, 15, 36120.
- Concert pitch; A440 (pitch standard); Scientific pitch. Wikipedia, the free encyclopedia, read on 28 September 2026.
- International Organization for Standardization. ISO 16:1975 Acoustics: Standard tuning frequency (Standard musical pitch).
- World Health Organization. Make Listening Safe: recommendations on safe listening levels.
The generator makes the sound in the browser (Web Audio). On this page it starts in the tuning A4 = 432 Hz with the melody, the opening four bars of the Prelude in C major by Johann Sebastian Bach (BWV 846), and a 5-minute timer. It can also play the note A as a pure tone and a chord of the notes A, E and A (108, 161.82 and 216 Hz in the 432 Hz tuning; 110, 164.81 and 220 Hz in the 440 Hz tuning). The frequencies of all notes are computed in equal temperament from A4 = 432 Hz or A4 = 440 Hz, and the tuning can be switched while the sound plays. Nothing is a recording.