sleep Delta band
Deep Sleep Induction
2.5 Hz beat · 285 Hz carrier · 3 phases · 45 min · beginner
The only session here that reaches the delta band, and the only one that never brings you back up. It opens in alpha like everything else in the catalogue and then keeps descending.
The beat and carrier in the heading are the main phase — the part of the session it was built around. They are not what plays for the whole length. Every programme here opens in the alpha band, wherever it is going afterwards, and most come back up before they finish. The full phase plan is on this page, and it is the honest picture of what you would actually hear.
Hear it
Thirty seconds rendered at the parameters of the phase named above — not an excerpt cut from the paid file, so the full deliverable never loads on a public page. The figures the player draws are computed from the audio or from plate mathematics; none of them is a measurement of your hearing.
What this actually is
Two and a half hertz is the slowest beat we publish. At this rate you stop hearing a pulse and start feeling a swell — the two channels drift in and out of step slowly enough that the ear reads it as the sound breathing rather than as a rhythm to track.
Delta is the slowest band we publish, below four hertz. A beat this slow is felt as a long swell rather than heard as a pulse, and it sits below the three-hertz floor of the photosensitivity risk band, so no delta programme raises the flashing question at all.
The full phase plan
Three phases across forty-five minutes, and the beat falls at every step: ten hertz for the first ten minutes, six for the next ten, then two and a half for the remaining twenty-five. It crosses three bands on the way down — alpha, theta, delta — which no other programme here does, and it has no return phase. The session simply ends at the bottom.
| Phase | Role | When | Beat | Band | Carrier |
|---|---|---|---|---|---|
| Relaxation | induction | 0–10 min | 10 Hz | Alpha | 432 Hz |
| Theta Transition | deepening | 10–20 min | 6 Hz | Theta | 396 Hz |
| Deep Delta | main | 20–45 min | 2.5 Hz | Delta | 285 Hz |
Where the 285 Hz carrier comes from
Solfeggio. A tone the Solfeggio tradition associates with restoration and with returning something to its original form.
The Solfeggio set is a twentieth-century construction attributed to a medieval hymn. The hymn is real; the frequency assignments were worked out much later and are not found in it.
The carrier is the pitch you actually hear. The binaural difference — the part that makes this a structured session rather than a tone — lives between the two channels and is set by the beat, not by the carrier. Choosing one carrier over another is a tonal choice, the way picking a key is a tonal choice. It is not a functional one.
What this is
The name says induction, and it is the name this programme has always had. What it is, is a forty-five minute structured audio session built to the parameters above: it opens in alpha, descends through theta, and spends its long middle in delta, which is the shape it was designed around. It belongs at the end of a wind-down you already have. It is not a treatment for insomnia — sleep that stays broken is a matter for a clinician, and audio is not one.
Who it is for
People who already have a wind-down and want something to occupy the last part of it. Long enough that you are not meant to hear the end.
This is one of the starting points a session is built from, published in full — phase plan, parameters and an excerpt you can hear — so you can see what you are buying before you buy it. What arrives is rendered to the plan on this page, in three formats, at one price.
Choose your download
Audio
7 EUR
WAV, FLAC, and MP3. The files are rendered in advance to the plan above, so they are available immediately; Polar takes the payment and Fluctara sends a one-use download link to the purchase email. No account is required.
Audio + video
14 EUR
WAV, FLAC, MP3, and 1080p MP4. The files are rendered in advance to the plan above, so they are available immediately; Polar takes the payment and Fluctara sends a one-use download link to the purchase email. No account is required.