432 Hz and the solfeggio myth

This one deserves a direct answer, because it is everywhere and because the honest version is more interesting than the myth.

What the claim is

That tuning music to A = 432 Hz rather than the modern standard 440 Hz makes it more natural, more harmonious with the universe, or better for you. And that a set of "solfeggio" frequencies — 396, 417, 528, 639, 741, 852 Hz — carry specific healing properties, with 528 Hz often described as repairing DNA.

Where it actually comes from

The solfeggio set was introduced in the 1970s by Joseph Puleo, who described deriving the numbers from a numerological reading of a Latin hymn in the Book of Numbers. That is the origin. It is a twentieth-century numerology exercise, not a recovered ancient tuning.

The names attached to the frequencies came later, and the DNA-repair claim attached to 528 Hz has no experimental basis at all. DNA does not have a resonant frequency in the audible range that sound in air could act on, and no study has demonstrated anything of the kind.

The 432 Hz story is similar. Concert pitch has drifted enormously across history and geography — surviving instruments imply reference pitches from roughly 400 Hz to over 460 Hz depending on the century, city and instrument. There was no single ancient standard for 440 to have replaced. The idea that 440 Hz was imposed for sinister reasons is a modern invention with no documentary support.

But people do report a difference

They do, and it is worth taking seriously rather than dismissing.

Two mundane explanations cover most of it.

It is quieter and slower. Music re-tuned to 432 Hz is usually also mixed, chosen and presented differently — calmer material, softer mastering. You are rarely comparing the same recording.

Pitch height genuinely affects perception. A tone 8 Hz lower is, trivially, lower. Lower carriers are perceived as warmer and less bright, and brightness is fatiguing over long listens. That is a real preference and a real reason to choose a lower carrier — it just is not mystical, and it applies equally at 430 or 435.

The one thing that is not happening is a special resonance at a magic number.

Pitch is not pulse

This is the confusion underneath the whole argument, and naming it clears most of it up.

Pitch is how high or low a tone sounds — 432 Hz, 528 Hz, concert A. Pulse is how often something repeats — 10 times a second, twice a second.

A brainwave rhythm is a pulse rate. Alpha is 8–12 cycles per second. There is no such thing as a 528 Hz brainwave; EEG activity tops out around 100 Hz.

So listening to a steady 528 Hz tone does not put your brain at 528 Hz, because that is not a thing brains do. It plays you a pitch near C5. Whether that pitch is pleasant is a genuine question about timbre and preference. It is not a question about entrainment, because nothing is repeating.

Modulate that same 528 Hz tone ten times a second, though, and you have a 10 Hz stimulus riding on a 528 Hz carrier — a pulse and a pitch, doing different jobs. That is what every session here is.

Once you can hold those two apart, most of the solfeggio literature reads differently: it is making claims about pitch while borrowing the vocabulary of pulse.

What carrier pitch actually does in this kind of audio

Here it gets genuinely useful, because carrier choice is not arbitrary — it just matters for physical reasons rather than numerological ones.

• It sets the timbre. A 108 Hz carrier is felt as much as heard; a 400 Hz carrier is clearly a tone. This is the single biggest factor in whether you can tolerate a session for forty minutes.
• It constrains binaural delivery. Binaural beating relies on the auditory system resolving timing differences between the ears, which fails above roughly 1 kHz and is clearest between about 400 and 500 Hz. A carrier chosen for its symbolism can put the session outside the range where the mode works at all.
• It interacts with your playback. Laptop speakers roll off steeply below about 200 Hz. A carrier at 108 Hz on a laptop is partly inaudible.

None of those depend on the number being 432.

Why some of our sessions use these numbers anyway

You will find 432 Hz and similar carriers in this catalog, and we would rather explain that than pretend otherwise.

They are there because they sit in a genuinely useful range and because listeners look for them. A 432 Hz carrier is a good carrier — low enough to be warm, high enough to survive a phone speaker, well inside the range where binaural delivery works. Every one of those is true of 430 Hz and 436 Hz too.

What we do not do is attach a claim to the number. The session specification tells you the carrier, the beat, the envelope and the noise bed, and none of the descriptions promise that a particular pitch does something a neighbouring pitch would not.