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 a finished file, because sessions are built to order and yours does not exist yet. 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 does not claim
The name says induction. It is a name, and it is the one this programme has always had. What is being sold is a forty-five minute structured audio session built to the parameters above. It will not put you to sleep, it is not a treatment for insomnia, and if you are not sleeping we would rather you saw someone about it than bought this.
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.
Nothing here is for sale yet. These are the starting points a session can be built from, published so you can see the whole range before anything is priced.