Brown note

The brown note is a hypothetical infrasonic frequency that would cause humans to lose control of their bowels due to resonance. Attempts to demonstrate the existence of a "brown note" using sound waves transmitted through air have failed.

The name is a metonym for the common color of human feces. Frequencies supposedly involved are between 5 and 9 Hz, which is below the lower frequency limit of human hearing. High power sound waves below 20 Hz are felt in the body, not heard by the ear as sound. The only other vibrations titled with colors are the colors of noise and blue notes.

Physiological effects of low frequency vibration

Jürgen Altmann of the Dortmund University of Technology, an expert on sonic weapons, has said that there is no reliable evidence for nausea and vomiting caused by infrasound.

High volume levels at concerts from subwoofer arrays have been cited as causing lung collapse in individuals who are very close to the subwoofers, especially for smokers who are particularly tall and thin.