What Is 174 Hz? The Lowest Solfeggio Tone in Numbers, Where It Came From, and How We Use It

174 Hz is the lowest of the nine tones known as Solfeggio frequencies. In this channel’s tracks it is most often the bottom layer of long sleep pieces. This page separates three things: what 174 Hz is as a sound, where the tradition ends and research begins, and how we actually use it.

What 174 Hz is (by calculation)

One practical point: small phone speakers barely reproduce 174 Hz itself. They are weak below about 200 Hz, so what you hear on a phone is mostly its overtones (348 Hz, 522 Hz…). To hear the actual pitch, use headphones or a speaker with real bass.

Distance to the other Solfeggio frequencies

100 cents is one semitone. Many of these distances fall between the intervals of ordinary music, which is one reason Solfeggio combinations sound unusual.

Where the number came from

The Solfeggio system became widely known after Leonard Horowitz’s 1999 book, which describes Joseph Puleo deriving 396, 417, 528, 639, 741 and 852 from verse numbers in the Book of Numbers. That account comes from the system’s proponents; no independent historical source has been found. 174, 285 and 963 Hz were added later. The often-repeated link to medieval Gregorian chant does not hold: there was no hertz unit and no fixed pitch standard in the Middle Ages, and the hymn Ut queant laxis gave us the syllables do-re-mi, not frequencies.

What research says (as of October 2026)

No peer-reviewed study testing the effects of 174 Hz in people was found. Among the nine Solfeggio frequencies only 528 Hz has human studies, and those are small (the 528 Hz research summary). The descriptive names attached to 174 Hz come from the tradition and from listeners’ accounts.

How we use it

We use it as the foundation of long sleep tracks. The 8-hour triple stack (174 + 396 + 432 Hz) was rebuilt in October 2026 after we found its master was clipped and that its right channel beat at 2 Hz on its own; the corrected version puts 174 Hz in the left ear and 176 Hz in the right.

As of October 2026, 26 of this channel’s published videos use 174 Hz (14 long-form). Some of the long ones:

• Ultimate Deep Sleep · 528 → 432 → 396 → 174 Hz Descent (8 Hours, Black Screen) (488 min)
• Held by Ancient Cedars in Pre-Dawn Mist · 174Hz Sacred Forest (480 min)
• 174Hz Deep Sleep 8 Hours · Black Tortoise of the North (480 min)
• Great Buddha · 8 Hour Deep Sleep · 174Hz 🗿 (478 min)
• 174Hz Sleep Music (60 min)
• 7.83 Hz Schumann Resonance · 1 Hour Earth Pulse (No Loops) (60 min)

None of these tracks plays a bare 174 Hz sine wave for its whole length; the tone is wrapped in overtones and layered with other sounds so it can be listened to for a long time.

Listening notes

• Start quietly. Pure tones reach the ear more strongly than music at the same level.
• Pure tones are for checking a pitch; for relaxing, a composed track is a better fit.
• This page does not promise any physical or mental effect. If you have health concerns, please see a doctor.

Frequently asked questions

Can I hear 174 Hz on a phone?

You will hear the track, but mostly its overtones; phone speakers produce little at 174 Hz. To check the pitch itself, use headphones with the Frequency Lab.

Is 174 Hz related to 7.83 Hz (the Schumann resonance)?

No. 7.83 Hz is an electromagnetic resonance and is not an audible pitch. 174 Hz is an ordinary audible tone in the low range of the human voice.

Should I play a pure 174 Hz tone all night?

We do not recommend it. Pure tones tire the ear; a track composed as music is better suited to long listening.

Related

• Solfeggio frequencies: the nine tones
• Frequency Lab (play and compare)