Overview
- A peer‑reviewed paper by Carlos Jurado and Torsten Marquardt published this week in Scientific Reports presents human measurements and a biophysical model showing that intense infrasound can trigger nerve signals, overturning the simple idea that sounds below roughly 16–20 Hz are always inaudible.
- The team found that at very low frequencies the usual inner hair cell pathway is too weak, so cochlear support cells and outer hair cell–generated electrical potentials act on inner hair cell membranes to produce neural excitation.
- That alternative pathway explains why infrasound lacks a clear tone and often feels like a hum or internal vibration, and it produces a strongly non‑linear loudness response where small pressure increases can yield large jumps in perceived intensity.
- Natural differences in the structure and electrical sensitivity of cochlear support cells offer a biological reason some people are strongly disturbed by low‑frequency noise from heat pumps, ventilation systems and wind turbines while others are unaffected.
- The authors and reporting outlets say the finding points to gaps in standard acoustic measurement and hearing tests and could affect clinical assessment and noise regulation, but further work is needed to define exposure thresholds and practical measurement or mitigation steps.