Being adequately hydrated is crucial for your vocal health, especially to prevent and manage voice disorders. And it is possibly the easiest thing you can do to make sure your vocal folds are functioning well. But do you know what happens when you don't drink enough? Or live in a dry climate?
Keep reading to learn the negative effects of dehydration, and what you can do to help keep your vocal folds happy.
One of the most widespread myths of internet is that we need to drink 6-8 glasses of water every day. While easy enough to remember, it can be too much (or too little) for different people (1). Apparently, there is no set amount that would be enough for every single body. But vocal folds are 83% water, which makes them especially susceptible to being negatively affected by dehydration (2).
Besides, when singing or speaking, they must collide over 100 times a second, sometimes over 500 times. That's a serious workload!
Being the tiny membranes that they are, it makes sense to provide them with their main component. Hence, this has been the recommendation of voice teachers, Ear-Nose-Throat doctors and Speech Language Therapists alike for vocal hygiene.
But is drinking water enough for properly hydrating your vocal folds?
Types of Hydration
When you drink water, it must first pass through the digestive system and be absorbed into the bloodstream before reaching the vocal folds. This is called systemic hydration, and it can take up to 4 hours for organs to reach optimal hydration levels after being dehydrated (don't quote me on this — found it in my voice pedagogy journal, but I sadly did not note the original source at the time).
So it takes a long time to actually hydrate your vocal folds systemically when you feel a bit under the weather.
But there is another way of hydrating them.
Superficial hydration can be increased by inhaling humidified air through steam, humidifiers or nebulisers. This works much quicker than systemic hydration.
However, the benefits of hydration on the voice were based mainly on anecdotal reports and findings have been inconsistent (2,3).
Luckily, two CCC-SLPs Mahalakshmi Sivasankar and Ciara Leydon (3) have reviewed the literature for studies on vocal fold physiology and the effects of hydration.
On a side note — I'm not sure whether it is more comforting or disturbing that most of these studies were on excised animal larynxes.
Anyway, on to the study.
Effects of Hydration on Vocal Fold Function
Just like it is possible to hydrate vocal folds systemically and superficially, it is also possible to have systemic and superficial dehydration.
Systemic hydration can affect the vocal folds in a few ways, like vibration patterns, amplitude of vocal fold motion and phonation threshold pressure.
Phonation threshold pressure (PTP) is dependent on several properties, like thickness of the vocal fold tissue, its viscosity and elasticity. In theory, increasing the water content of the superficial layer of the vocal folds should increase viscosity. This should result in a decrease in the PTP, making it easier to start voicing.
But research did not exactly support this hypothesis. In fact, a study has found that superficial hydration did not impact the viscosity enough to cause a significant change in the vocal folds. Another study, however, found that dehydration by exposure to dry air increased the PTP.
Another correlation that comes up in the literature is between dehydration and vocal damage — Eeek!
When dehydrated, the epithelial barrier of the vocal fold tissue might be disrupted. Just like the epithelial layer of the skin, it has a protective function for the layers underneath. So when it is compromised through dehydration, the vocal folds might become more susceptible to damage.
So what happens with superficial dehydration?
If you are healthy and have relatively good nutrition habits, this is actually more common in everyday life than systemic dehydration.
Because it can happen with exposure to too dry air, mouth breathing or even rapid breathing.
And studies have found that when vocal folds are dehydrated, the vocal range is decreased and it can take more vocal effort to perform the same tasks, increasing fatigue.
If you are remotely serious about your vocal hygiene or performance, these are serious implications.
Go sip on some water before reading more — I'll wait.
But How Much Does It Really Change Your Voice?
To sum up the above, studies have found that having optimum hydration levels can help:
Your vocal folds to be less susceptible to damage,
Decrease PTP, requiring less pressure to start voicing,
Lower jitter and shimmer in voice,
Increase your vocal range,
Lower vocal effort and fatigue.
So yes, your voice teacher was right: Hydration does make a significant difference in your vocal hygiene and quality.
Well, hydration cannot be considered separately from the highly complex overall mechanism that vocal folds reside in: Your body.
There are so many factors that affect the performance of your voice, from hormones and nutrients to how well-rested you are on a given day. So there is no guarantee that you will experience all of the benefits of increased hydration, especially if you have good hydration habits to begin with.
Also, this study does not reach a conclusion on whether superficial or systemic hydration is more effective. Until further research gives a definitive answer, it is probably a good idea to balance your efforts between both.
Majority of the research so far shows that having optimum hydration levels affects the voice positively. Especially if you are actively using your voice in your daily life, making sure you are adequately hydrated can help you maintain your vocal health and performance.
Also, remember that hydration does not only mean drinking water: Inhaling steam or nebulised water can be quite effective as well, as is having a humidifier in your room if you live in a dry climate.
A final note for tea and coffee drinkers — contrary to what you may have been told, caffeinated drinks do count as water and do not cause dehydration (4).
Enjoy your next cup!
Mayo Foundation for Medical Education and Research. (2020, October 14). How much water do you need to stay healthy? Mayo Clinic. Retrieved November 27, 2021, from https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256.
King, R.E., Steed, K., Rivera, A.E., Wisco, J.J. & Thibeault, S.L. (2018). Magnetic resonance imaging quantification of dehydration and rehydration in vocal fold tissue layers. PLOS ONE 13(12). https://doi.org/10.1371/journal.pone.0208763
Sivasankar, M., & Leydon, C. (2010). The role of hydration in vocal fold physiology. Current opinion in otolaryngology & head and neck surgery, 18(3), 171–175. https://doi.org/10.1097/MOO.0b013e3283393784
Katherine Zeratsky, R. D. (2020, August 27). The myth about caffeine and dehydration. Mayo Clinic. Retrieved November 27, 2021, from https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/caffeinated-drinks/faq-20057965.
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