Some research even suggests that sound, and not even very loud sound, can kill on the spot. Low-frequency noise, such as that produced in large buildings by ventilation and heating ducts or wind effects, can match and resonate with the frequencies of our body cavities. Sounds with frequencies of eight cycles per second, for example, vibrate in time with the chambers of the heart, increasing the potential for thrombosis. Seven-cycle sounds trigger a harmonic with the brain’s 9 Hz alpha-wave frequencies, causing fatigue, headaches, and nausea.

George Michelsen Foy, Zero Decibels, loc. 45