FourThirtyTwo

432 Hz vs 440 Hz: how to compare them yourself before converting

The difference between 440 Hz and 432 Hz is subtle, so the best way to choose is to hear the same passage both ways. FourThirtyTwo’s live A/B preview lets you switch between the original and a retuned version while the song plays, before any file is written.

Updated September 30, 2026 · 4-minute read · iPhone and iPad

Quick steps

  1. Import a song you know well.
  2. In Preview Before Converting, press play.
  3. Tap Retuned and Original to switch while it plays.
  4. Try other targets from the Target menu, then create the file you prefer.

How big is the difference?

Small. Going from A = 440 Hz to 432 Hz lowers every note by 1.8% (31.8 cents), about a third of a semitone. The melody, harmony, tempo and length all stay the same. Some people hear 432 Hz as a little darker or softer. Others struggle to tell them apart. The only way to know which you prefer is to listen to the same passage both ways.

Loudness over time for the original (top) and the 432 Hz version (bottom). Every section lines up exactly; only pitch differs. Loudness over time for the original (top) and the 432 Hz version (bottom). Every section lines up exactly; only pitch differs.
Same song, same timing: loudness over time for the original (top) and FourThirtyTwo’s 432 Hz export (bottom). Both are exactly 1:08.000 long, so switching between them in the preview keeps you at the same point in the song.
Show the measured values
Loudness envelopes compared in 50 ms windows.
Timing offset between the two envelopes0 ms
Envelope correlation (1.0 = identical shape)0.997
Length, original → export1:08.000 → 1:08.000

Step by step

  1. Import a song you know well

    Choose something familiar with sustained notes: vocals, piano or strings make pitch differences easier to hear than drums. After importing (how to import), the convert screen shows the Preview Before Converting card with the waveform, a scrubber and play controls.

    Convert screen with the Preview Before Converting card, Original selected in the A/B control, the waveform, and play and 15-second skip buttons

  2. Play and switch

    Press play, then tap Retuned. The same passage keeps playing, now at 432 Hz. Tap Original to go back. The switch is instant and nothing is written to a file yet.

    Preview playing at 0:11 with Retuned selected and the playhead shown on the waveform

  3. Try other targets

    Tap the Target frequency and choose 415, 440, 444 or 528 Hz, or Custom…. The retuned preview follows your choice immediately, so you can compare several tunings against the original in one listening session.

    Target menu with presets 415, 432, 440, 444 and 528 Hz and a Custom option

  4. Create the version you prefer

    When you’ve decided, tap Create 432 Hz File (the button shows whichever target you picked). If you’d rather keep the original, there’s nothing to undo because nothing has been written.

How to make it a fair test

  • Loop the same 10–20 seconds. Use the scrubber or the 15-second skip-back button so you’re comparing like with like.
  • Use headphones or a quiet room. Small pitch differences are easier to judge without background noise.
  • Switch several times. The first switch always sounds “different”. Preferences often settle after a few rounds.
  • Try it blind. Ask someone else to tap Original or Retuned without telling you which, and see whether you can pick them out and which you prefer.
  • Check the source first. If the recording isn’t really at 440 Hz, the comparison won’t be 440 vs 432. Use Auto-detect to confirm.

If the Original/Retuned control is greyed out, the source and target are the same, so there’s no difference to preview. Pick a different target or check the source tuning.

About the audio in these screenshots. The tracks (“Lanternfield”, “Quiet Meridian” and friends by “Demo Ensemble”) are short original pieces synthesized for these guides and saved as ordinary MP3, M4A, WAV and FLAC files. They’re part of our tuning test set, which you can download. Everything else is real: the app imported them through the normal Files picker, analyzed and converted them on the device, and the charts are measured from the exact files it exported.

A preference, not a prescription

There’s no objectively better concert pitch. 440 Hz is today’s common standard, and 432 Hz is an alternative some listeners enjoy. FourThirtyTwo doesn’t claim that any tuning has health or other benefits. It gives you an accurate, side-by-side way to hear both and keep the one you like.

Try it on your own music

FourThirtyTwo is a one-time purchase for iPhone and iPad. No subscription, no account, and your audio never leaves your device.

Requires iOS or iPadOS 18 or later.