Solfeggio 639
A traditional Solfeggio tone; a bright, gentle listen for calm, connected moments
Ready to try Solfeggio 639?
15 min free · Headphones recommended
What is the 639 Hz frequency?
639 Hz is one of the traditional Solfeggio tones, a set of pitches from devotional and chant music. There is no audio study of 639 Hz. Participants in a singing-bowl study reported feeling calmer and less tense (Goldsby et al., 2017); that study was not a trial of 639 Hz. Freqium offers it as a calm listening tone.
Proposed mechanism
A steady, brighter tone. Like other calm sounds, it can make it easier to slow down; no effect specific to 639 Hz has been shown
Traditional uses
These are the uses traditionally associated with 639 Hz. They come from cultural practice, not from clinical trials, so read them as intentions for a session, not as outcomes.
Who is this for?
People often choose 639 Hz for:
Experience it yourself
Reading about a frequency is one thing. Feeling it is another.
The science behind 639 Hz
Brainwave entrainment is the idea that the brain’s electrical activity can fall into step with a steady rhythm you hear. A related response, the Frequency Following Response (FFR), can be measured with EEG.
For 639 Hz the reasons are mostly traditional. The papers below are background on sound and the brain, not trials of this frequency.
Published Research
How to use Solfeggio 639
Suggested session
20-30 minutes, whenever you want a calm listen. Individual experiences may vary
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Use headphones
Over-ear or in-ear, at a low volume. They keep the tone clear without turning it up.
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Find a quiet space
A calm room makes it easier to settle in and notice how you feel.
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Be consistent
A short session every day is easier to keep. Notice how you feel and adjust.
Safety information
Listening to frequencies is generally considered safe for most adults. However, certain conditions require caution. Consult a healthcare professional before use if any of the following apply:
- ⚠If you are pregnant, use an implanted device, or a clinician is already caring for you, talk with them before listening
- ⚠Stop if you feel dizzy or distressed
- ⚠This is a wellness tool, not a medical device
This information is for educational purposes only. Freqium is not a medical device and is not intended to diagnose, treat, cure, or prevent any disease.
When Science Listens to Sound
Dr. Tamara Goldsby
Researcher, Department of Family Medicine · University of California San Diego
Study summaryAn observational study of a single singing-bowl meditation session, without a control group.
In 2017, Tamara Goldsby and colleagues at UC San Diego asked 62 adults to rate how they felt before and after a one-hour sound meditation with singing bowls, gongs and bells.
After the session, participants reported feeling less tense and more at ease on standard mood questionnaires.
The study had no control group, so it cannot say how much of the change came from the sound itself rather than resting quietly for an hour.
We share it as an honest picture of where sound-meditation research is: promising, early, and worth trying for yourself.
Self-reported tension
Lower
After one session, 62 participants, no control group (observational)
Sound meditation is being studied seriously — and you can try it tonight.
Effects of Singing Bowl Sound Meditation on Mood, Tension, and Well-being. Journal of Evidence-Based Integrative Medicine, Vol. 22, Issue 3
Now you know the science. Feel it for yourself.
Experience 639 HzHear 639 Hz for yourself.
You’ve read what is known and what isn’t. Put on headphones and notice how Solfeggio 639 feels to you.
Start 20-Minute Session15 min free · Headphones recommended