Belching (also known as burping, ructus, or eructation)
involves the release of gas from the digestive tract
(mainly esophagus and stomach) through the mouth.
It is usually accompanied with a typical sound and,
at times, an odor. In most parts of the world, especially
in formal situations, audible burping is considered
impolite. Public belching tends to be received in
a manner similar to flatulence...