Four instruments. Spatial places a sound on a sphere (HRTF), now with an elevation booster and phone head-tracking. Binaural beats feed each ear a different tone. Nervous system has the evidence-backed ones: EMDR-style bilateral, and 40 Hz gamma. Chamber is the experiment: a plucked bass ringing a resonant stone room that sloshes around your head. Headphones required.
Drag on the radar to place the sound. You're the head at center; the notch is forward, rings are distance. Elevation is the hard axis — the booster fakes the pinna cue that a generic ear model can't.
That feeling from the fly-by is frisson — aesthetic goosebumps. It's triggered by rising intensity, a bright partial emerging, spatial motion, and a touch of acoustic roughness. Send a shiver, then dial in the scratch.
Auditory illusions that get stranger in space. Shepard rises forever without ever getting higher; the helix spirals a sound around and over you; the Doppler pass whooshes by with a real pitch drop. Best with head tracking on.
A pure tone in each ear, a few Hz apart. The "beat" isn't a real sound — your brainstem makes it from the mismatch. The Gateway presets add Monroe's noise bed and the classic Focus frequencies (honestly: relaxing, not a portal).
The two with the most real evidence. Bilateral (EMDR) ping-pongs sound ear to ear — the mechanism behind a real trauma therapy. 40 Hz gamma is an amplitude-pulsed tone (the research approach, not a binaural beat).
What a bass player who wandered into chemistry, ancient-Egyptian stonework, and Feynman's coupled oscillators might build. A plucked bass line excites a bank of high-Q resonators tuned like a granite room; the overtones sit at different points around your head, and the energy sloshes left to right the way two coupled pendulums trade motion. Put on head tracking and walk your ears through the standing wave.
Hide a sound at a place AND a pose. Arm it standing where you want it, aiming your phone how you want; walk away; then Seek and steer the phone-triangle into the ring to match the saved heading + tilt. Aiming plus being there is the anti-spoof: a faked GPS pin can't also reproduce the exact on-site pose. Indoors GPS is coarse, so the pose does the fine work — try it between rooms in your apartment.
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Left-right is easy: your brain reads the tiny time and loudness gap between ears. Up-down lives almost entirely in the spectral notches your own outer ear carves, and that notch slides from ~6 kHz (below) to ~12 kHz (above), horizon near 7 kHz. A generic ear model can't match your ears, so elevation stays fuzzy. The booster here nudges that band (a Blauert directional-band cue); the real fixes are a personalized HRTF and head tracking. Springer 2025 · spectral weighting & elevation. And "8D audio" is simpler than this — it's just auto-panning plus reverb, no true elevation.
The beat is a perception your brainstem invents from the ear mismatch; it has no direction. For the autonomic side (heart-rate variability, relaxation, sleep) there's modest randomized-trial support; the "retunes your brainwaves / boosts focus" claim is weak. The Gateway Tapes are Robert Monroe's Hemi-Sync: binaural beats plus a noise bed and guided voice, organized into "Focus" levels (10 = mind awake/body asleep, alpha; 12 = expanded, theta). The 1983 CIA "Gateway Process" report is real but wobbles between neuroscience and pseudoscience — treat the astral-travel framing as folklore, the relaxation as plausible. beats & ANS · the CIA report.
Alternating left-right stimulation is the core of EMDR, an established trauma treatment. Leading theory: it taxes working memory while you hold a memory, draining its charge; imaging shows amygdala/limbic modulation. Auditory works like the eye-movement version. This slider is the mechanism to feel, not a substitute for a clinician. PLOS One · NIRS study.
An amplitude-pulsed 40 Hz tone (and light) — the "GENUS" approach. In mice it cut amyloid ~37–53%; small human trials are safe and hint at slower decline and better sleep, but it's early and unproven as treatment. It is not a binaural beat — the sound itself pulses 40 times a second. Frontiers 2025 · Wiley 2025.
No health claim here, just honest acoustics: high-Q bandpass filters ring like a resonant room; a plucked bass excites them (sympathetic resonance); the overtone series is spread across the sphere; and a slow cross-fade moves energy between the left and right clusters exactly like Feynman's two coupled pendulums trading their swing. The "Egyptian granite room" is a tuning choice, not a mystical one.