A low, rumbling noise people compare to an idling diesel engine,
the hum might infuriate one person, while the man standing next
to him hears nothing at all. It occurs the world over: there's
the "Bristol Hum" in Great Britain, the "Bondi Hum" in Australia
and the "Taos Hum" in New Mexico. One of the earliest reports of
the hum came from Taos locals, who speculated that the sound was
caused by magma moving beneath thin sections of the earth's
crust or underground engines powering the nearby national
science lab at Los Alamos. In 2003, two scientists studied
radio-frequency emissions in Kokomo, Ind., in an attempt to
explain that city's hum. They examined the town's 18 cell
towers, the airport and the multiple broadcasting stations.
Their conclusion: "If blood brain barrier opening by RF
absorption plays a role in the acoustic transduction process,
the radiation levels found here may be sufficient to excite
auditory responses." Translation: You might not just be hearing
things.