Biometric sound synthesis

Your body
becomes
sound.

Praenox reads your HRV, sleep architecture, and stress — then generates a therapeutic soundscape engineered for your exact physiological state. Not generic. Not approximate. Yours.

+44%
Deep sleep vs baseline
+30%
REM sleep vs baseline
+22%
Sleep duration vs baseline
56.5
Avg HRV · stress 22.9
Downloads
Real data · baseline 2022 vs Praenox era · through Jun 18, 2026

Before vs after.
The numbers
don't lie.

Two eras on one timeline. The left half is the raw Zepp baseline — tracked nights before Praenox. The right half is every night after Praenox started, brought right up to today. The dashed marker is the switch-over. No cherry-picking.

Live — updated daily

Every data point is entered as-is from the device — including the outliers you can see in the chart. The spike in deep sleep, the near-zero REM night, the recovery dip — all real, all included. If anything, the broken nights make the trend harder to achieve, not easier.

The gap in the baseline between 2022 and late 2025 is not missing data — the watch was worn but tracking was off and the app was never checked. No interest in the numbers at the time. That is exactly what unmanaged baseline looks like.

Deep sleep
+44%
13.1% → 18.8%
REM sleep
+30%
20.0% → 26.0%
Sleep duration
+22%
5.5h → 6.7h
Avg HRV
56.5 ms
Avg stress: 22.9
Before Praenox After Praenox
Free vs Pro vs Developer

Pick your
level.

Free reacts to today. Pro learns your patterns, detects chronic deficits, and acts before the decline starts. Developer adds everything in Pro plus the tools to test, verify, and see how the engine actually works.

Free
Praenox
Free · Windows · forever

already downloaded

Sound engine
Full biometric fingerprint synthesis — HRV, HR, deep sleep, REM, and stress each drive a different audio dimension
6 protocols — Parasympathetic Restore, Delta Induction, Cortisol Reset, REM Restore, Cardiac Calm, Maintenance
Binaural beats, isochronic pulses, breath guide, noise color, solfeggio — all tuned per session
Palette & style selection — nature, instruments, Tibetan bowls, sacred harmonics, and more
MP3 export — listen on any device with earbuds
Intelligence
Personal baseline calibration from your history — HRV, HR, sleep, stress medians
Protocol selected daily from your worst metric vs baseline
No long-term pattern detection — reacts to each day independently
No spike smoothing — protocol changes whenever your metrics change
No sleep debt tracking or forced protocol carry-over
Tracking
Pattern Drift charts — HRV, sleep, stress history
Day comparison — any two saved days side by side
Data Vault — import, export, automatic backup
Pro
Praenox Pro
One-time · lifetime licence
Join waitlist
Coming soon
Everything in Free, plus
Fusion engine — learns your HRV trajectory and predicts decline before it happens. Forces preventive protocol when Act risk is detected
Pro
Stability Mode — locks protocol across multiple days when a chronic pattern is confirmed, not just reacting to today's worst metric
Pro
Sleep Debt Gate — detects chronic undersleep vs your personal baseline; forces Delta Induction until you catch up (3 consecutive sufficient nights to close)
Pro
HRV Velocity — tracks rising/falling trend across days; responds to trajectory, not just today's value
Pro
BiometricContext — full history feeds each generation; personal sleep target calibrated from your data, not a fixed 7h rule
Pro
Learning Report — Outcome Learning closes the loop: compares each session's frozen recovery snapshot against your actual next-day recovery, classifies it Helped/Hurt/Stabilized/Neutral, and rolls that into learned weights for protocol, style, palette, layers, beat bands, solfeggio, duration and story shape once a combination hits 3 evaluated sessions. Shown side by side with live Fusion accuracy and the active precedence layer for any selected day
Pro
Fusion stages
Stage 1 — Signal (0–20 HRV entries): Watch/Act banners appear, engine is building your model
Stage 2 — Locked (21–59 HRV entries): Act risk forces protocol; sessions become preventive
Stage 3 — Predictive (60+ entries + accuracy >55%): Self-calibrating thresholds; sub-labels Calibrating → Tuning → Predictive
Engagement & streaks
Points, levels, badges, export confirmation system (+13 listened / −5 skipped)
Streak shields — earn 1 shield every 7 streak days (max 2); fires automatically on missed days
HMAC-protected achievement profile — isolated per user account
Developer
Praenox Developer
One-time · lifetime licence
Join waitlist
Coming soon
Everything in Pro, plus
Learning Report manual refresh — re-run Outcome Learning across your entire saved history on demand, not just on entry save; scope readout shows exactly how many soundscapes have been evaluated out of how many saved
Dev
QA Runner — 50+ automated logic tests across generation, achievements, Fusion, outcome learning, and a dedicated trust suite, run on demand
Dev
History Simulator — generates full synthetic biometric histories to reach any engine state instantly (Fusion Stage 2/3, sleep debt, stability mode) without waiting weeks for real data
Dev
Sound Signature Verification — confirms playback and export used the exact same generated layers, catching drift between what was generated and what was heard
Dev
Visual & Runtime Diagnostics — inspect generated layer parameters, palette weighting, and the full rationale trail behind any soundscape, live
Dev
Development Log — full timestamped event trail of every generation, playback, and achievement action, for debugging
Dev
Who it's for
Not a more-powerful Pro — same sound engine, same Fusion, same points and levels
Built for people who want to verify the engine themselves, inspect what's actually happening under a session, or run the same QA suite used internally
FeatureFreeProDeveloper
Biometric fingerprint synthesis
6 biometric protocols
MP3 export
Personal baseline calibration
Progress charts & day comparison
Long-term pattern detection
Fusion engine (predictive)
Stability Mode
Sleep Debt Gate
HRV Velocity tracking
Streaks, shields & milestones
Outcome Learning / Learning Report
QA Runner (50+ automated tests)
Synthetic history simulator
Sound signature verification
Visual & runtime diagnostics
Development event log
PriceFreeOne-time · lifetimeOne-time · lifetime
Pro · Fusion engine

Control
before it
happens.

Free reacts to each day in isolation. Pro learns your trajectory — it knows when your HRV is falling before you feel it, and forces the right protocol before decline arrives.

Join Pro waitlist
Coming soon
01
Signal
0–20 HRV entries
Fusion watches and alerts. Watch/Act banners appear. No protocol is forced — the engine is building your personal model from your history.
02
Locked
21–59 HRV entries
Act risk detected forces the protocol. Sessions become preventive — the engine overrides the daily fingerprint when a decline pattern is confirmed.
03
Predictive
60+ entries · accuracy >55%
Self-calibrating thresholds. Sub-labels emerge: Calibrating → Tuning → Predictive. The model is now specific to you, not generic population baselines.
Free vs Pro vs Developer · FAQ

Questions,
answered.

Why Free changes protocols daily, what Pro actually learns, how Fusion, Sleep Debt and streaks work, and what the Developer tools are actually for. Switch tabs to see each plan's answers.

The free version has no persistent Stability Mode and no Sleep Debt detection. It looks only at the health data you entered for that specific day — HRV, resting heart rate, deep sleep %, REM %, stress.

It then picks the protocol based on which single metric is furthest below your personal baseline (e.g. HRV too low → Parasympathetic Restore, deep sleep too low → Delta Induction, stress too high → Cortisol Reset).

Because your daily biometrics naturally fluctuate, the "worst metric" often changes day to day. The app is not broken — it is faithfully reflecting your daily variability.

Yes, but only your personal baselines, not behavioural patterns. It continuously updates your normal HRV, resting HR, typical deep sleep %, REM % and stress using all saved days, then uses them to calculate each new day's deficit.

What it does not do:

  • Learn long-term patterns (e.g. "your HRV has been falling for 5 days")
  • Predict next-day recovery
  • Force a protocol across multiple days
  • Detect sleep debt or force Delta Induction for chronic undersleep

No. There is no spike-smoothing rule. If your HRV jumps from 50 ms to 80 ms overnight, the protocol for that day is based on the new value directly.

There is no "stable mode" that locks you into a single protocol for several days. If the protocol changes often, it's because your biometrics themselves are oscillating — the free version simply shows you that truth.

No, it's working as designed. The free version doesn't analyse chronic conditions — it reacts to each day's data independently.

High stress one day, low REM the next, good recovery the third produces Cortisol Reset → REM Restore → Maintenance. That's not a loop — it's a reflection of your changing state. To respond to underlying patterns instead of daily noise, that's what Pro was built for.

Six protocols, automatically selected from your biometric fingerprint:

  • Parasympathetic Restore — general deficit, no single metric dominates
  • Delta Induction — deep sleep % significantly below baseline
  • Cortisol Reset — stress significantly above baseline
  • REM Restore — REM % significantly below baseline
  • Cardiac Calm — resting heart rate significantly above baseline
  • Maintenance — all metrics near or above baseline

The protocol label appears in the "Analysis" panel after generation.

Yes — try two things:

  • Enter data every day — gaps make the previous-day baseline less stable.
  • Look at your raw numbers — if HRV, stress and sleep are genuinely stable for a week, the output stays similar. If they aren't, the app will change.

If you want the engine to learn and stop jumping, that's exactly what the paid version was designed for.

Not at all. The free version is excellent for understanding how your daily biometrics shape a therapeutic soundscape, experimenting with palettes and styles, and getting a fresh, data-driven session every night.

It just isn't designed to target chronic patterns or stabilise your protocol over time. For that, you'd need Pro.

No, it's working as designed. The app has learned your baselines and is now focusing on your most persistent issue. Priority order, highest to lowest:

  • Sleep Debt Gate
  • Stability Mode
  • HRV Velocity (rising/falling)
  • Biometric Fingerprint (HRV, HR, deep %, REM %, stress)

If your sleep is regularly shorter than your baseline, the Sleep Debt Gate opens and forces "Sleep Debt Delta Recovery" until you catch up — three consecutive sufficient nights close the gate.

Fusion sits on top of the priority system. It can force a protocol in Stage 2 or 3 when an Act risk is detected, but it never bypasses Sleep Debt or Stability Mode.

Fusion prevents tomorrow's failure. Sleep Debt addresses today's deficit.

  • Stage 1 — Signal (0–20 HRV entries): shows Watch/Act banner, doesn't force protocol.
  • Stage 2 — Locked (21–59 entries): Act risk forces the protocol; session becomes preventive.
  • Stage 3 — Predictive (60+ entries + accuracy > 55%): self-calibrating thresholds and sub-labels.

Stage 3 sub-labels by accuracy: < 55% → Calibrating, 55–69% → Tuning, ≥ 70% → Predictive.

Open Charts → "Your Optimal Sleep" card. It shows your personal baseline (e.g. 442 min) and confidence level (Low / Medium / High). This comes from your own history — not a fixed 7-hour rule.

  • Current (live) — recomputed now using your current baselines.
  • Snapshot (frozen) — locked at generation. Playback and export always use this.

They differ when your baselines improve over time. Both are correct — just different reference frames.

To protect the soundscape linked to that date. Locked fields become read-only and the delete button is disabled.

You can edit a locked day (confirmation required), but only future generations use the new values — the existing soundscape keeps its original snapshot forever.

Export awards points immediately and creates a pending confirmation in Milestones.

  • Listened (+13 pts) — confirms, awards bonus.
  • Skipped (−5 pts) — records a skip penalty.
  • If not confirmed within 36 hours, the pending state expires.

Preventive sessions (Fusion Stage 2+) use +13 listened, −8 skipped.

Shields — earn one shield every 7 streak days (max 2). If you miss 2+ days without opening the app, a shield automatically fires and your streak survives. You do nothing. The shield_user badge unlocks on first shield use.

  • HRV entries < 21 → "X more HRV days until Stage 2"
  • HRV entries 21–59 → "X more HRV days until Stage 3"
  • ≥ 60 entries, accuracy < 40% → "Stage 3 needs 40% accuracy — currently X%"
  • ≥ 60 entries, accuracy 40–55% → no label (in Stage 2, waiting for accuracy > 55%)
  • Stage 3 active (accuracy ≥ 55%) → sub-label Calibrating / Tuning / Predictive

The missing label at 40–55% is intentional — no more days are needed, you just need to keep marking LISTENED until accuracy climbs above 55%.

The other protocols (Cortisol Reset, REM Restore, Cardiac Calm, Maintenance) aren't gone — they're lower priority. To see them, sleep enough: 7 consecutive days with sleep ≥ your personal baseline (shown in Charts → Sleep Optimiser).

Once the Sleep Debt Gate closes, the engine cycles through the other protocols based on your daily fingerprint.

Every generated soundscape freezes a recovery snapshot at generation time. Once you mark a session LISTENED and the next day's entry is saved with a real HRV reading, Outcome Learning compares that next-day recovery against the snapshot and classifies the result:

  • Helped — recovery rose ≥ 3 points
  • Hurt — recovery dropped ≥ 3 points
  • Stabilized — recovery was already declining and the decline was arrested
  • Neutral — no meaningful change

Skipped sessions are excluded — a session you never heard says nothing about whether it worked. Once a protocol, style, palette category, layer, beat band, solfeggio frequency, duration, or story shape has at least 3 evaluated sessions, it earns a learned weight (0.6x–1.5x) that eases in gradually rather than snapping, so one rough night can't undo weeks of good data.

Fusion and Outcome Learning read the same saved history but track different things: Fusion predicts your next-day recovery and can force a protocol during a risk pattern; Outcome Learning tracks whether the soundscape itself actually helped. Fusion now also factors Outcome Learning's verdict on its forced protocol into its own confidence score. Both are shown side by side on the Learning Report tab, along with the active layer and precedence order for the selected day — Sleep Debt Delta Recovery first, then Fusion-forced protocol, then Outcome-learned weighting, then plain biometrics.

Nothing about the sound engine, Fusion, or scoring changes — Developer runs the exact same core as Pro. What's added is a dedicated Development tab with tooling to test and verify that core yourself: a QA Runner, a synthetic history simulator, sound signature verification, and visual/runtime diagnostics.

It's a different tier for a different kind of user, not a "more powerful" Pro.

An automated suite of 50+ logic tests covering context and generation, engagement, achievements, Fusion, data integrity, and outcome learning — plus a dedicated trust suite that checks things like snapshot freezing and per-user data isolation.

Run it on demand from the Development tab. It's the same suite used internally before every release.

Fusion Stage 2 needs 21+ HRV entries, Stage 3 needs 60+. Building that up with real nightly data takes weeks. The simulator generates a full synthetic biometric history so you can put the engine into any state — Fusion Stage 2/3, sleep debt, stability mode — instantly, without touching your real health data.

Every play and export captures a signature of the exact layers, seed, and parameters used. Verification confirms playback and export actually used the same generated soundscape — catching any drift between what was generated and what was heard or exported.

No. It's fully hidden and disabled in Pro — there's no button, no hidden shortcut, nothing to unlock later. It only exists in the Developer build.

No. If you just want the sound engine, Fusion, and the full recovery loop, Pro is the complete product. Developer exists for people who want to see how the machine works, verify it themselves, or run the same tests used internally — it doesn't change your day-to-day sessions at all.