The module remains passive, listening for inbound pairing queries from master platforms like mobile phones or central computers.
During 14 isolated days in winter 2025–2026 (low geomagnetic activity, Kp < 2), we identified 43 events where pressure pulsations at 0.1–0.5 Hz correlated with magnetic field oscillations (specifically the horizontal component H). Figure 1 (conceptual) shows a 20-minute window where cross-correlation coefficient exceeded 0.72 at zero lag, indicating a common atmospheric wave source.
Infrasound, ULF waves, atmospheric coupling, ionospheric variability, HEAR05, magnetometer array
Funded by NSF AGS-2234117. The authors thank the Boulder infrasound facility for calibration support.
uses a commercial V-shaped frequency response curve. This profile deliberately boosts sub-bass performance ( ) to compensate for external environmental ambient noise.
With the rise of personal audio devices delivering sound at 94-110 dB, early noise-induced hearing loss is now appearing in teenagers. HEAR05 is the only rapid test sensitive enough to detect "ear fatigue" before it becomes permanent tinnitus.
