In this excerpt from Curious Behavior by Robert R. Provine, prepare to learn more about the science, culture, and “art” of flatulence than you ever thought possible. From the time of ancient Greece to the performance halls of 19th century France, the gaseous expulsions of the human digestive tract (and the muscular control therein) have fascinated the world’s great thinkers. What do medicine and science have to say about vibration-induced auditory communication?
The bottom trace of a fart’s acoustic structure is a sound spectrum that shows strong harmonic structure, as reflected in the regular stack of frequency bands that are multiples of a fundamental frequency of around 150 Hz at mid-burst. The fart has a tonal quality and is clearly not a noisy blast with a random distribution of frequencies. The fart also has a periodic, pulsatile quality (amplitude modulation). A raspberry or Bronx cheer, produced by placing the tongue between the lips and blowing, makes a similar sound. Farts lack the structural stereotypy of laughs, coughs, sneezes, and hiccups, and their duration is determined by the highly variable supply of available gas.