Thai people are generally very modest and graceful, but there are exceptions. For instance, they cannot seem to do anything with their respiratory or gastro-intestinal tracts without dramatic vocalization.
Burping is not merely the release of air trapped in the stomach; it is an opportunity to block the diaphragm and project an operatic tone into the proceedings. A simple cough is amplified with as much enthusiasm from the voice box as can be mustered. Someone hawking and spitting into a sink is quite an elaborate song and dance. All of this is merely quaint, the real show is presented upon puking.
Our home in our Peace Corps days was in a thinly housed neighborhood of a small city. There was an egalitarian mix of very nice homes of prosperous people and lots of Tobacco Road shacks housing families who were very, very poor. In the mix was a condo block populated mostly by young Thais with good jobs and cars, the burgeoning middle-class. Only the condos had air-conditioning; the rest of us slept as though together, hearing every sound together, not only bird sound, bug sound, frogs, and lizards, but also lovers’ quarrels, impromptu midnight karaoke parties, drinking bouts, and fights. Some shooting of guns was involved, also a bit of puking.
The vomiting was theatrical in the extreme. Never just the rushing fluid sound, but always accompanied by screaming. Vomit, as you know, is a caustic fluid, bearing as it does a large amount of stomach acid. Good judgment dictates that one should allow the flow to be accomplished with as much speed as possible. Screaming is exactly the wrong idea. I constricts the throat and impedes the flow, the result is painful. This is obvious, because the vomit-screaming is always followed immediately by a pained cry, further constricting the throat and causing further pain.
It is always my wish in these scribblings to offer a reasoned explanation, or at least to speculate on some plausible explanation. Alas, here I have nothing to offer. Like so many other things, this vocalizing is a mystery to me.