◆ HEAT-BEAT ACOUSTIC MITIGATOR · 4-channel beat generator · periodicity detector · Web Audio → Bluetooth speaker

○ audio idle ◇ peak: —

Beat Channels — each: two oscillators $f_A$, $f_B$ → envelope mod $|f_A - f_B|$

5.0%
22.0°C

Live Waveform + Spectrogram

Top: time-domain mixed signal of all active channels. Bottom: rolling FFT — peaks at $f_A$ and $f_B$ carrier tones, with sidebands at $f_A \pm f_m$ and $f_B \pm f_m$ from intermodulation.

Periodicity Detector — auto-correlation peak (Eq. from CCT)

RMS amplitude —
Peak frequency —
Period T (samples) —
Detected period —
Phase coherence —
Beat rate Σ —
Auto-correlation R(τ) of mixed audio over a 480 ms window. Peak = dominant periodicity. If peak ≈ 4.2 Hz → your heater / HVAC resonance is being entrained.

Auto-Optimizer — find best beat for target mod rate

4.20 Hz
80 Hz
→
400 Hz
Idle — click "Optimize" to find best beat at target mod rate.

Heat-Wave Presets + Honest Physics

THE MATH — Two oscillators at fA  and  fB produce $x(t) = \sin(2\pi f_A t) + \sin(2\pi f_B t) = 2\cos\big(\pi (f_A - f_B) t\big)\,\sin\big(\pi (f_A + f_B)\,t\big)$. The envelope cos(π·Δf·t) oscillates at Δf = fA − fB, and this is the "beat" you perceive. If Δf ≈ 4.2 Hz matches a low-frequency thermal oscillation (HVAC, ventilation fan, wind), the two systems can entrainedly lock, reducing the thermal cycle's prominence.
EMPIRICAL CONTEXT — Your observation (180/184 Hz beat for low-frequency noise) maps onto an existing literature: masked tone interference and binaural entrainment are well-established effects. The MAYBE-extension to heat waves is plausible but not guaranteed.
Three possible mechanisms: (1) HVAC compressor vibration interferes with the local fan loop, slightly derating its efficiency. (2) Acoustic-thermal psychroacoustic coupling (ambient sound affects perceived thermal comfort). (3) Resonance with the body's ≈0.1 Hz thermoregulatory oscillation through harmonic chains.
HONEST LIMITS — True phase-cancellation of a heat wave at its thermodynamic frequency requires physical cooling, not sound. Sound carries ~10⁻³ watts per BT speaker. A heat wave releases ~10⁸ watts per city block. The audio path is best framed as interference, not cancellation.
Bluetooth adds 40-200 ms latency that breaks phase coherence. For best results: wired speakers, or low-latency codec (aptX LL, LC3, or AppleAAX). Place speakers at ear level, multiple units spaced 1-2 m for spatial coverage. Start at master volume 5%, increase slowly.
DEPLOYMENT CHECKLIST —  [ ] Wired to Bluetooth codec with verified low latency.  [ ] Speakers 60 cm above floor, 1-2 m apart.  [ ] C1: 180/184 Hz, C2: HVAC-derived beat, C3: 0.1 Hz circadian LFO over C1.  [ ] Run for 30 min minimum before judging subjective effect.  [ ] If user reports any ear discomfort, lower volume or stop.