The podcast investigates "The Hum," a low-frequency drone heard by 2% of people worldwide. It examines Taos and Kokomo case studies where residents describe sounds like idling engines that often evade scientific recording. The discussion contrasts audible hums with Earth’s seismic vibrations and explores theories ranging from gas pipelines to biological causes like otoacoustic emissions. It frames the Hum as a mysterious intersection of environmental science and human physiology.