A living dreamscape
A sonic world that breathes with your surroundings. Not a playlist. Not ambient noise. Something in between — a dreamscape that listens, shifts, and pulls you quietly sideways from the ordinary.
Soundliminal generates a living, dreamlike soundscape — a perceptual shift rather than a product. It listens to the world around you through your phone's microphone, feels your movement through the gyroscope, reads the time of day and your surroundings — and from all of that, builds a sound world that has never existed before and will never exist again.
Every session is unrepeatable. The dream is always the same, and never the same.
Choose a dream from the library. Put on headphones — the illusion is designed for intimate listening and requires them. Let the dreamscape breathe with your surroundings for a few minutes before judging it; it takes time to weave itself around you.
Optionally add a song from the in-app catalog: it will play woven into the dream, and the dream will listen back — reacting to the song's energy, rhythm, and texture in real time.
Swipe right to leave. Drag up or down anywhere to shift the volume. Double-tap to locate any active satellites — their remaining time appears as a short code above the void.
Two objects can orbit the black hole at the center of the player: a probe and a telescope. They are optional — sent into the void through a small in-app tip — and their presence keeps the app free for everyone else.
The probe orbits in a slow Keplerian ellipse, moving faster near the event horizon and slower at apoapsis — a small cluster of three bright dots aligned along its velocity tangent, periodically emitting a signal that curves to the bottom of the screen. The telescope sweeps across in sine-arc transits at different heights each pass, flashing in morse-like bursts whenever it transmits. Double-tap the screen to locate either; their remaining time appears as a code: P2H30M for probe, T1H15M for telescope.
Every dream is built from several concurrent layers that blend and shift in real time.
The probe's orbit is computed frame-by-frame from Kepler's equation, solved by Newton–Raphson iteration:
where M is mean anomaly, E is eccentric anomaly, ν is true anomaly, e = 0.52 is orbital eccentricity, and a is semi-major axis. Velocity direction is computed as a forward finite difference (Δν = 0.006 rad), aligning the three-dot probe body tangent to its instantaneous trajectory.
The telescope path is a sine arc: y = baseY − h·sin(π·progress), where h (arc height, 20–50 pt) is seeded per transit using a linear congruential generator — seed = (cycleN × 1664525 + 1013904223) mod 2³¹ — giving stable, reproducible randomness without any stored state.
Signal dots follow a quadratic Bézier-like curve: x(t) = (1−p)²·x₀ + (1−(1−p)²)·xc, y(t) = y₀ + p²·(yc − y₀), where p ∈ [0,1] is normalized time, (x₀, y₀) is the emission position, and (xc, yc) is the bottom center of the screen.
The tone layer draws from the nine solfeggio frequencies — a set of intervals whose digit sums reduce exclusively to 3, 6, or 9, the pattern Tesla described as the key to the universe:
Drone frequencies and phantom tones are tuned to octave multiples of these values, so every harmonic produced by the engine sits on a node of the same numerical lattice. The root drone, when not overridden by a song's key, defaults to 174 Hz (or its sub-octave at 87 Hz) — the lowest solfeggio, associated with grounding and physical sensation.
The connection to Chladni figures is not metaphorical. Ernst Chladni showed in 1787 that a plate vibrating at a resonant frequency organizes sand into standing-wave nodal lines — the geometry of the sound made visible. The governing equation is the biharmonic wave equation for thin plate flexure:
where w is the plate displacement, D the flexural rigidity, E Young's modulus, h plate thickness, ρ density, and ν Poisson's ratio. The eigenfrequencies of this system — the values at which the plate rings — depend on its geometry and boundary conditions. The solfeggio frequencies sit near the eigenfrequencies of certain rectangular and circular plates of natural materials, which is why they were rediscovered empirically across many cultures long before the equation was written.
In Soundliminal the orbiting particles around the black hole are a temporal Chladni figure: the ring of matter that accumulates at the photon sphere is where the gravitational wave equation's solution has a nodal surface — matter that neither falls in nor escapes, tracing the geometry of the field in the same way sand traces the geometry of sound.
Soundliminal is an artistic and creative audio experience. It is not a medical device and is not intended to diagnose, treat, cure, or prevent any physical or mental health condition. References to solfeggio frequencies, resonance, and their associated names reflect historical and cultural tradition, not medical or therapeutic claims.
Listen at a safe volume. Prolonged exposure to audio at high levels can cause permanent hearing damage. The app is designed for intimate headphone listening — if others nearby can hear your headphones, the volume is too loud.
Do not use Soundliminal while driving, cycling, operating machinery, or in any situation that requires your full attention. The experience is intentionally immersive.
Soundliminal is built and maintained by one person. If something doesn't feel right, write to andresrobert@icloud.com.
Soundliminal does not collect, store, or transmit any personal data. There are no accounts, no analytics, no tracking, and no network requests made during a session. Everything the app does happens entirely on your device.
The app requests microphone access to listen to your ambient environment. This audio is processed in real time within the app to shape the dreamscape — for example, a loud room may shift the noise bed, and quiet moments allow subtler sounds to emerge.
The Dream Echoes feature captures short fragments of ambient audio in RAM, processes them into unrecognizable textures, and plays them back as part of the sound experience within the same session. These fragments are never written to disk, never transmitted, and are automatically discarded when the session ends.
Microphone access is optional. The app functions without it, but the environment-reactive features will not be available.
The accelerometer and gyroscope are used to detect movement — walking cadence, stillness, and orientation. This data is read locally and used only to modulate the audio in real time. It is never stored or transmitted.
Optional satellite tips are processed entirely through Apple's in-app purchase system. Soundliminal does not handle or store any payment information. Apple's privacy policy governs those transactions.
Questions about privacy can be directed to andresrobert@icloud.com.
Last updated: July 2026