Frequencies are easier to hear than to read about. This tool plays the nine Solfeggio tones, 432 Hz and 440 Hz right here on the page. No sign-up, no app.
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The same short melody is played with concert pitch at 432 Hz and at 440 Hz. Using only your ears, pick which one is 432 Hz.
Guessing gets you half. If you score 8 or more out of 10, you can probably hear the difference.
A slightly different pitch is played in each ear. Use headphones or earbuds (over speakers it sounds different).
Start quiet. Higher tones hit the ear harder at the same volume. No sound on iPhone? Turn off the silent switch on the side of the phone.
What this tool does
- Play a tone: switch between the Solfeggio frequencies from 174 Hz to 963 Hz, plus 432 Hz and 440 Hz, with one tap. Type a number to play any pitch from 20 to 2000 Hz.
- 432 Hz or 440 Hz?: the same melody is played at both concert pitches and you pick which is 432 Hz by ear. Play as many rounds as you like; your score is kept.
- Binaural beats: a slightly different pitch in each ear produces a slow pulsing sensation inside your head. Try it with headphones.
All sound is generated on your own device as you listen. Nothing is streamed, so it uses almost no data.
What I’d like you to hear first
I make music built on the Solfeggio frequencies and publish it on YouTube. From the maker’s side, reading that “528 Hz is the love frequency” and actually hearing a plain 528 Hz tone are two very different experiences.
Try this. Leave the volume where it is and play each tone in order from 174 Hz up to 963 Hz. You will notice that the higher the tone, the harder it hits your ear. The volume setting has not changed, yet 963 Hz sounds much louder and harsher than 174 Hz.
That is because human hearing is more sensitive to higher pitches. So when I make a track, I turn the higher frequencies down and wrap them in a softer timbre. The number is the same, but a bare pure tone is not something you can listen to for long. Keeping the frequency while making it comfortable is the core of the work. I wrote about that trial and error in the production note on the 174 + 396 + 432 Hz sleep track.
The nine Solfeggio tones, 432 Hz and 440 Hz at a glance
This table shows where each frequency falls on the ordinary musical scale. “Nearest piano note” is the closest note in equal temperament at A4 = 440 Hz, with the offset in cents (one cent is a hundredth of a semitone).
| Frequency | Commonly called | Nearest piano note | More |
|---|---|---|---|
| 174 Hz | the “foundation” tone | F3 −6 cents | Read more |
| 285 Hz | the “restoration” tone | C♯4 +48 cents | — |
| 396 Hz | the “release” tone | G4 +18 cents | Read more |
| 417 Hz | the “change” tone | G♯4 +7 cents | Read more |
| 432 Hz | Concert pitch in 432 Hz tuning | A4 −32 cents | Read more |
| 440 Hz | International standard pitch | A4 | Read more |
| 528 Hz | the “love frequency” | C5 +16 cents | Read more |
| 639 Hz | the “connection” tone | D♯5 +46 cents | Read more |
| 741 Hz | the “expression” tone | F♯5 +2 cents | Read more |
| 852 Hz | the “awakening” tone | G♯5 +44 cents | Read more |
| 963 Hz | the “cosmic” tone | B5 −44 cents | Read more |
Two things stand out. First, 741 Hz is almost exactly F♯5, a note that already exists in ordinary music. Second, 285 Hz, 639 Hz, 852 Hz and 963 Hz sit roughly halfway between two piano keys, pitches that a normally tuned instrument cannot play. That is one reason Solfeggio tracks sound unusual.
Can you actually tell 432 Hz from 440 Hz?
The gap between 432 Hz and 440 Hz is about 32 cents, roughly a third of a semitone. Heard one after the other, most people notice that the pitch differs. But hearing just one and naming it as 432 Hz is hard even for trained listeners.
Try it in the “432 Hz or 440 Hz?” tab. Pure guessing gets you half, so 8 or more out of 10 is a reasonable bar. Whatever you score, it is an answer you checked with your own ears. For the history and the research, see 432 Hz vs 440 Hz.
How binaural beats work
When the left ear hears 200 Hz and the right ear hears 206 Hz, you perceive a slow wobble at the difference between them, here 6 Hz. That wobble is not in the air; it arises when the brain combines the two signals. That is why it needs headphones and does not work the same way over speakers.
By convention the size of the difference is named after brainwave bands (delta, theta, alpha, beta). That naming does not mean listening has been shown to shift your brainwaves into that band. The state of the research is covered in the binaural beats guide.
Before you use it
- Start quiet. Pure tones tire the ear faster than music. Avoid long continuous playback.
- A pure tone is not music. These sounds are for checking what a frequency sounds like. For relaxing, a track made as music is a better fit.
- This page does not promise any effect on body or mind. Human studies on the effects of specific frequencies are still few (the state of 528 Hz research).
- If you have epilepsy or any health concern, avoid binaural beats and ask a doctor. Do not use them while driving or operating machinery.
Related tool
Hearing Age Test: find out how high a pitch you can still hear.
To hear these as music
The frequencies you tested here are available as finished music on YouTube, from long sleep tracks to short meditation pieces.
Open the MuZenCosmos channel on YouTube
This article does not guarantee any medical or health benefit and is not a substitute for professional medical care. If you have any health concerns, please consult a physician or other qualified professional.
