An old singing coach once explained to me that hiccups are a remnant from our fetal days. In the months before birth, our breathing muscles must develop, but actual breathing would damage the lungs by forcing amniotic fluid in and out of them. The solution is to spasm the diaphragm, but force shut the epiglottis before anything can be taken in.[sup]1[/sup] Thus: the hiccup.
Since it’s caused by the diaphragm, it can be solved by consciously controlling the diaphragm.
Most people, when they inhale, use both their diaphragms and their rib cages, dropping the diaphragm and expanding the rib cage to increase lung volume. If you eliminate the chest movement, and allow your diaphragm to do all the work of inhalation, the conscious control of the muscle will eventually cause the spasms to subside.[sup]2[/sup]
It’s probably all pseudoscience, but hey, a couple minutes of diaphragm-breathing always cures my hiccups.
[sup]1[/sup]I have two reasons to doubt this guy. First, I believe that our lungs are full of fluid before birth, so there’s no reason to avoid filling them. Second, he was a music teacher. How much could he possibly know about physiology?
[sup]2[/sup]If it doesn’t work as a hiccup cure, at least you’ll improve your breathing for the purposes of proper vocal technique.