What 432Hz means
432Hz is a tuning, not a sound. Musicians tune to a reference note, the A above middle C. The international standard, ISO 16, sets that A at 440Hz. Tuning it to 432Hz instead lowers every note by the same small amount: about 31.8 cents, or roughly a third of a semitone.
So in 432Hz tuning only one note, A4, actually sits at 432Hz. Everything else moves with it. Middle C, for example, goes from about 261.6Hz to 256.9Hz.
| 440Hz tuning | 432Hz tuning | |
|---|---|---|
| The A above middle C | 440Hz | 432Hz |
| Middle C | 261.6Hz | 256.9Hz |
| Difference | 31.8 cents lower (about 1/3 semitone) | |
| Status | International standard (ISO 16) | An alternative some listeners prefer |
| Sounds like | Standard | Slightly lower; some call it warmer |
432 vs 440: can you hear the difference?
Side by side, yes. A third of a semitone is far more than the roughly 5-cent change most people can notice, so the same song at 432Hz sounds a little lower. Heard on its own, with nothing to compare, most people can't tell which tuning they're hearing.
Do people prefer it? In a blind listening test by acoustics professor Trevor Cox, listeners rated 432Hz and 440Hz about the same. Many "432Hz" tracks online are ordinary recordings pitch-shifted down, which you can't verify by ear.
A short history of 432Hz and 440Hz
Concert pitch was never fixed. Historical tuning forks run from about 409Hz to over 460Hz; Handel's 1740 fork sits at 422.5Hz. France set A at 435Hz by law in 1859, after singers complained that pitch kept creeping up.
Verdi is the name you'll see attached to 432. He backed the French 435 for his Requiem in the 1870s, then came to slightly prefer 432, mainly because it was easier on singers, and in 1884 Italy's military bands were ordered to use it. His real concern was one standard everywhere, not anything mystical.
440Hz won through decades of negotiation. The US adopted it in 1936, a 1939 conference in London run by the British Standards Institution recommended it, and ISO made it the standard in 1955 and 1975. Many orchestras today actually tune a little higher, around 442Hz. The popular story that Goebbels or the Nazis imposed 440Hz is false.
Does 432Hz music help you sleep? What the research says
The research is a handful of small pilot studies. The best known, a 2019 study of 33 people, found heart rate about 4.8 beats per minute lower with 432Hz music than with the same music at 440Hz, right at the edge of statistical significance, with no sleep measures. The only sleep study, of 12 patients, didn't compare 432 with 440 directly. A dental anxiety trial found both tunings lowered anxiety compared with no music, with no difference between them.
What is well supported is music itself: a Cochrane review found that listening to music probably improves how well people with insomnia feel they sleep, whatever the tuning. So pick 432Hz if you like how it sounds. Don't expect it to do something 440Hz can't.
Claims that don't hold up
You'll read that 432Hz is "the frequency of the universe," matches the Earth's Schumann resonance, heals the body or repairs DNA, often alongside 528Hz. None of it has scientific support. The Schumann resonance is an electromagnetic effect around 7.8Hz, not a sound, and science writers have found no evidence that musical tones repair anything. We think 432Hz tones are lovely to fall asleep to, and that's the whole claim.
Is there 432Hz white noise?
No, and anything sold that way is mislabeled. White, pink and brown noise have no pitch: their energy is spread across every frequency, so there's nothing to tune. Only tones and music can be tuned to 432Hz.
What works beautifully is combining them: a soft 432Hz tone low under brown noise. The noise does the masking, the tone adds warmth. In the Sleepy Noise app you can layer them and set each level.
Our three 432Hz tones
Warm Pad is a soft A major chord. Night Chord drifts between A minor and F major over about 45 seconds. Deep Drone is a low A with a soft fifth. Each note is a pair of tones a fraction of a hertz apart, so it shimmers gently, and each one's level wanders on its own, so the sound never settles into a loop. The chords use just intonation built on A = 432Hz: notes like 108Hz, 162Hz and 216Hz.
They're part of the Tuned to 432Hz pack in Sleepy Noise Lifetime, with a Singing Bowl tuned the same way. This page plays a 60-second preview of each.
How to use 432Hz tones at night
Keep the volume low, lower than you'd play music. Try a tone alone for winding down, then mix it under brown noise or rain for the night. If you'd rather it not play all night, set a 30 or 60 minute timer; it fades out instead of stopping.
Frequently asked questions
What is 432Hz?
A tuning where the A above middle C is 432Hz instead of the standard 440Hz. Every note ends up about a third of a semitone lower.
Is 432Hz better than 440Hz?
It's a matter of taste. In a blind listening test, people rated 432Hz and 440Hz about the same.
Does 432Hz music help you sleep?
Calm music can help some people feel they sleep better. There's no good evidence that 432Hz tuning helps more than 440Hz.
Is 432Hz a healing frequency?
No. There's no reliable evidence that it heals or repairs anything, and claims about the frequency of the universe have no scientific basis.
Why is music tuned to 440Hz? Was it the Nazis?
No. 440Hz came out of decades of standards work, including a 1939 London conference run by the British Standards Institution, and became the ISO 16 standard. The Goebbels story is a myth.
Did Verdi use 432Hz?
He used the French 435Hz for his Requiem and later slightly preferred 432Hz because it was easier on singers. Nothing he wrote mentions healing.
Is there 432Hz white noise?
No. Noise has no pitch, so it can't be tuned. Only tones and music can be tuned to 432Hz, which is why our tones mix so well under brown noise.
Are the 432Hz tones free?
You can play 60-second previews here. The full Tuned to 432Hz pack comes with Sleepy Noise Lifetime, a one-time purchase.
