Even the nerds among singers often do not know the facts about Acid Reflux Disease, as we in the business more commonly refer to GERD. We more commonly think about reducing the foods that exacerbate our symptoms. It is however important to know that certain foods actually weaken the function of the Lower Esophageal Sphincter (LES), which is supposed to prevent stomach acids from backing up into the esophagus and throat.
In my last post I spoke about the environmental effects on vocal efficiency. However I concentrated mainly on faulty technical habits that could be acquired by exposure to poor speech and singing models that influence us at a young age before we are conscious of the negativity of such influences.
GERD is another environmental effect that can have very serious effects on the quality of the voice. Chronic burning and irritation of the vocal fold tissues cause unevenness at the edges, which prevent natural fold closure. The remedy is usually pressed phonation, which prevents natural fold lengthening and reduce range. In such circumstances, a natural higher voice could default to a lower tessitura and not sound convincing in that repertoire.
It is possible that most singers have GERD to some degree. A low level of GERD may not cause range loss, but might cause just enough irregularity at the fold edge to induce a low level of pressed voice. This would reduce the flexibility of the folds slightly and also prevent the ability to sing softly. For a tenor, the effect on career viability may be negligible, since viable tenors are also fewer. However for a soprano this could make the difference between viability and not since vocal quality is reduced by GERD.
The most important thing I have learned from the videos below is that there are specific foods that weaken the LES. It may be possible to return the LES to its natural effectiveness by avoiding the foods that cause the dysfunction. Alcohol, caffeine, and fried and fatty foods are the culprits. Other acid inducing foods aggravate the symptoms.
I recommend viewing the videos here to have a more informed understanding of the problem.