Infrasound Raises Stress in Buildings

A controlled lab study found that exposure to inaudible low‑frequency sound (around 18 Hz) increased salivary cortisol and self‑reported irritability in participants, even when layered under different types of music. The effect occurred without conscious detection, suggesting infrasound from HVAC, traffic, or infrastructure could subtly worsen mood and stress in everyday indoor settings. — If replicated, this links a ubiquitous, overlooked environmental factor to measurable stress, which matters for urban planning, occupational health, building codes, and debates about nuisance vs. health harms.