In this episode of pplpod, we investigate the strange and unsettling phenomenon known simply as “the Hum,” a low-frequency droning sound reported by small clusters of people around the world. The episode explores what it feels like to hear a constant diesel-engine-like vibration that others cannot detect, and why soundproofing often makes the experience worse instead of better. Drawing from historical reports and scientific investigations, the discussion breaks down the acoustic profile of the Hum, including its typical 30 to 40 hertz range, its pulsing modulation, its tendency to appear in cool weather and quiet environments, and the way low-frequency waves can travel through soil, buildings, water, and concrete.

The episode also examines the many possible sources behind the Hum, from blast furnaces, transformers, heat pumps, power station ...