Answer:
The man has hiccups; the bartender scares them away by pulling a gun.
Explanation:
Hiccups: The term "hiccups" is determined as the involuntary contractions of an individual's diaphragm (it is a muscle that tend to separate an individual's chest from his or her abdomen and is one of the responsible factor in breathing). However, the given involuntary contraction tends to cause a person's vocal cords to get closer that ought to produce hiccups' sound.
